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					        Thin Film Metallic Glasses: Preparations, Properties, and

                                     Applications

J. P. Chu1, J. C. Huang2, J. S. C. Jang3, Y. C. Wang4, and P. K. Liaw5                         Formatted: English (United States)
                                                                                               Formatted: Font color: Black, English
1 Department of Polymer Engineering and Graduate Institute of Engineering, National            (United States)
                                                                                               Formatted: English (United States)
  Taiwan University of Science and Technology, Taipei, Taiwan 10607                            Formatted: Font color: Black, English
                                                                                               (United States)
2 Department of Materials and Optoelectronic ScienceInstitute of Materials Science and         Formatted: English (United States)

  Engineering, Center for Nanoscience and Nanotechnology, National Sun Yat-Sen

  University, Kaohsiung 80424, Taiwan

3 Department of Mechanical Engineering, National Central University, 300 Chung-Da

  Rd. Chung-Li 32001, Taiwan

4 Department of Civil Engineering, National Cheng Kung University, Tainan 70101,               Formatted: English (United States)


  Taiwan

5 Dept. of Materials Science and Engineering, University of Tennessee, Knoxville,

  Tennessee 37996-2200, U.S.A.



      Metallic glasses, or called amorphous alloys, are homogeneous, isotropic,         and    Formatted: Font color: Black


free from crystalline defects. They have been studied extensively in the recent decade,

particularly in the bulk shape [1, 2]. These metallic glasses in the thin film form are also

interesting   to study because of their unique properties, such as high strengths and

amorphous nature. Shimokohbe and his group had fabricated Pd-based (Pd76Cu7Si17) and

Zr-based (Zr75Cu19Al6) thin film metallic glasses (hereafter abbreviated as TFMGs) first

used in micro-electro-mechanical systems (MEMSs) [3]. Compared to conventional

crystalline MEMS materials, TFMGs have the structure advantages,             including, for    Formatted: Font color: Black



                                                                                      Page 1
example, high strengths, and absence of grain boundariesy and segregation. TFMGs are.         Formatted: Font color: Black


tThus,     thought to have no size effect (Is it true?). Since TFMGs are a kind of            Formatted: Font color: Black


amorphous alloys,    in which their pPhysical and mechanical properties of TFMGs       can

be adjusted,   and mechanical properties can be as well as enhanced by changing their

compositions and by the precipitation of nanoscale particles (This is not a sentence).

Many TFMGs had been investigated for their glass-forming ability, thermal,             and

mechanical properties as well as potential applications. In this paper, we will review and

report some important and interesting results obtained from TFMGs in recent years.




1. Fabrication of TFMGs                                                                       Formatted: Font color: Black


     Physical vapor deposition (PVD),      including sputtering and evaporation,     is one

of common procedures for fabricating TFMGs. One of examples is the Zr-based TFMG,

which is deposited by sputtering   of a quaternary alloy target [5,6]. A broad Bragg peak     Formatted: Font color: Black
                                                                                              Formatted: Font color: Black
in Figure 1 shows that this Zr47Cu31Al13Ni9 TFMG sputtered from an alloy target is            Formatted: Font color: Black

mainly amorphous [6]. Note that throughout this paper, the compositions are in atomic

percent.    The tip of the Bragg peak hump at ~ 38º of 2θ (please kindly define θ.:

diffraction angle) indicates nanocrystalline phases dispersed in the amorphous matrix, as

confirmed by the transmission electron microscopy (TEM) result. An example of a TEM

bright-field image with a halo- ring selected area diffraction (SAD) pattern in Figure 2

obtained from a sputtered Zr61Al7.5Ni10Cul7.5Si4 TFMG reveals a typical homogeneous

amorphous matrix with dispersed nanocrystallites. Since the sputter deposition is

considered to be a non-equilibrium process, it becomes one of useful routes to obtain the

amorphous structure. To examine the mixing and vitrification behavior, binary Zr-Cu,


                                                                                     Page 2
Zr-Ti [7],   and Mg-Cu thin films are prepared by co-sputtering of elemental targets [8].

Figure 3 shows that the co-sputtered Zr-Cu and Mg-Cu films, with various intermetallic

compounds in the Zr-Cu equilibrium phase diagram, are found to be amorphous,

suggesting indicating the high vitrification tendency and good glass-forming ability [7,8].

It is   also suggested that the composition window for achieving fully amorphous thin

films is much wider than that for the bulk metallic glasses (BMGs). For example, the

ternary Zr-Cu-Ti system, particularly with high Ti contents, is normally difficult to be

fully vitrified in the bulk form. However, one can obtain amorphous Zr-Cu-Ti thin films

with an excessive Ti content as high as 19% by co-sputtering of elemental targets [9].



2. Properties of TFMGs

        A thorough knowledge base of thermal, physical,     and mechanical properties is

essential for the further applications of TFMGs. For instance, the thermal stability of the

amorphous phase of TFMGs is important for the microforming and annealing processes.           Formatted: Font color: Black


It has been reported that partially-crystallized TFMGs transform into various nanoscale

and amorphous structures during the annealing before the extensive crystallization takes

place in Zr- [4], Fe- [10],   and Cu-based [11] TFMGs. Crystalline phases are more

thermodynamically favorable than metastable phases formed in the as-deposited

condition [12]. In some elementally- modulated crystalline films, the solid-state

amorphization (SSA) within the interfacial nanometer regions could occur through

annealing-induced diffusion reactions [13]. Annealing of sputtered metastable TFMGs

are was found to yield the formation of various nanoscale and amorphous structures, thus

resulting in changes of electrical and mechanical properties. These property changes are

significant when annealed in the supercooled liquid region (ΔT), defined by the               Formatted: Font color: Black


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temperature range, ΔT = Tx - Tg, where Tg is the glass- transition temperature,   and Tx is

the crystallization temperature. To determine Tg, Tx , and other thermal properties, the      Formatted: Font color: Black


differential scanning calorimeter (DSC) is used. For the Zr-based (Zr47Cu31Al13Ni9)           Formatted: Font color: Black
                                                                                              Formatted: Font color: Black
TFMG, Tg and Tx temperatures are 758 K and 797K, respectively, with a ΔT of

approximately 40K [4]. As the film is annealed in within ΔT, the annealing-induced

amorphization occurs, as shown presented in Figure 4 [4]. TEM images show a series            Formatted: Font color: Black


of structure changes at different annealing temperatures. The film is completely

amorphous at 800K in ΔT,      as indicated in the microstructure and diffraction pattern.     Formatted: Font color: Black


The amorphization in ΔT yields film- property changes,     such as the surface roughness,     Formatted: Font color: Black


hardness,   and electrical resistivity (Figure 5 [4]). For instance, the surface roughness

decreases from 0.690 nm in the as-deposited state to 0.414 nm in ΔT. Fe- and Cu-based

films also exhibit the annealing-induced amorphization in ΔT [10, 11]. Low free energy        Formatted: Font color: Black


of the amorphous phase with sufficient thermal and interfacial energies between

nanocrystallites and glassy matrices could be considered as the driving force for the

vitrification during annealing in the ΔT region. The large negative heat of mixing and, d     Formatted: Font color: Black


hence,   the low free energy of the amorphous phase can be related to the amorphization

induced by annealing [4].

     For the mechanical- property evaluations, the nano-hardness is commonly used. For

the ternary Zr52Cu29Ti19 TFMG, sub-Tg annealing of the film induces the formation of

medium-range-ordered clusters,    and the nano-hardness is increased by 35% to 6.6 GPa        Formatted: Font color: Black


[9]. The micropillars with aspect ratios > 1.5 (1,600 nm in height and 980 nm in              Formatted: Font color: Black


diameter) , were milled by the focused ion beam (FIB) from a quaternary Cu51Zr42Al4Ti3

TFMG , to study the effects of individual structures arose resulting from different           Formatted: Font color: Black

                                                                                              Formatted: Font color: Black
annealing temperatures. The nanoindention results of micorpillars exhibit that the
                                                                                              Formatted: Font color: Black

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compression yield stress increases from 3.7 GPa at the as-deposited state to a maximum

value of 4.6 GPa at 723K in ΔT, followed by a decrease to 3.8 GPa at 798K above Tx. In         Formatted: Font color: Black


another Cu-based TFMG, the nano-hardness can reach a maximum value of ~ 9 GPa in

ΔT,     compared with ~7.6 GPa in a      of sub-Tg annealed sample at 698K. The SEM            Formatted: Font color: Black
                                                                                               Formatted: Font color: Black
image     shown in Figure 6 is a typical micorpillar failed by a single major shear band

with the plane of shear yielding about 41.4°, which indicates that the metallic materials in

both thin- film and bulk forms have the similar facture characteristics. Yet, it is worth

mentioning that , for the TFMG, the positive dependence of hardness with temperature is        Formatted: Font color: Black


unique and distinct from annealing-induced softening of conventional materials.

      Furthermore, multilayered TFMGs are getting more attentions lately. A recent work        Formatted: Font color: Black


demonstrates that the brittleness of a ZrCu metallic- glass coating can be alleviated by

placing a nanocrystalline metallic Zr underlayer [14]. The brittle TFMG on the top of the

micropillar becomes highly ductile and exhibits a plastic strain over 50% at room

temperature, as shown Figure 7(a) [14]. The nanocrystalline Zr layer acts like a buffer to     Formatted: Font color: Black


effectively dissipate the kinetic energy carried by incident shear bands. Nano-twinning

was induced in the nanocrystalline Zr layer. However, the metallic underlayer must be          Formatted: Font color: Black


sufficiently thick to be able to resist the incident shear bands. The thickness of the

crystalline layer would be dependent upon relatively the relative strengths of the

amorphous and crystalline layers. It is also found that this underlayer needs to be

sufficiently strong. When the nanocrystalline Zr underlayer is replaced by a softer

nanocrystalline Cu layer, no apparent deformation occurs in the TFMG top layer. Instead,

the softer Cu layer would be deformed plastically, as depicted in Figure 7(b) [14]. These

results suggest the life span of a brittle amorphous layer can be improved, by using an

appropriate metallic underlayer.                                                               Formatted: Font color: Black


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Simulations

     To understand the amorphous structure formation during deposition and

deformation behavior under indentation, molecular-dynamics (MD) models of the

Zr-based metallic-glass film (Zr47Cu31Al13Ni9) by simulating sputter deposition were

constructed.   The   as-deposited   films   were    further   used   for   the   subsequent

nano-indentation simulations.

     A thermal-control-layer-marching algorithm [15] was adopted to accelerate the

deposition. Without the algorithm, the computation for depositing a relatively thick film

is time-consuming. From this simulated deposition, the interface between the film and

substrate is considered to be ‘naturally’ formed, based on the MD principles. Figure 8

shows exhibits the results of the deposited Zr47Cu31Al13Ni9 film via the MD simulation

with an indent. It can be seen that pileup occurs around the indent, indicating the

homogeneous flow of the metallic glass under an intensive stress around the indenter. In

the deposition and indentation simulations, interatomic potentials, which that          are

derived from the many-body, tight-binding,     second-moment approximation (TB-SMA)

[16], were adopted to simulate the interactions among the four species of atoms (please

kindly describe the four pieces of elements) forming the metallic glass.

     In Figure 9, indentation load-displacement curves are shown presented at various

temperatures. Negative force indicates the attraction between the tip and the surface of

the film due to the weak interaction, while the tip is retracting from the sample. The

adhesion force may provide the valuable information about the surface energy of the film

in such a small dimension. As the temperature increases, the stiffness of the material

decreases. Moreover, the maximum load, corresponding to the same indentation depth,

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also decreases, indicating suggesting the softening of the material at high temperatures.

At   the 300 K case, the serrated flow in the load-displacement curve may be evident of

the shear-band activation or shear transformation in the shear- transformation zone (STZ)

[17]. The pop-in depth is about 2.5 Å, considerably smaller than what hasve been

reported in the literature, due to the large displacement rate used in MD. At higher

temperatures, the pop-in phenomenon is not clearly observed, consistent with the

experiment [17] (Please kindly give references).

     Using the definition of hardness, namely the ratio between the maximum load and

the projected area, the hardness of the film calculated from the MD simulation is

summarized in Figure 10. Based on our in situ indentation calculations at various

temperatures (labeled as solid diamonds in the figure), the hardness values of the

metallic-glass film decrease from about 7 GPa to about 5 GPa with the increase of

temperature from 100 K to 800 K. The dashed line indicates the linear- curve fit of the

MD data. The scattering of the MD data is due to the noise in the force calculation ofin

MD. It is found that the magnitude and decreasing rate of the hardness, about 2 MPa/K,

with respect to the temperature are in agreement between MD calculations and

experiments. The experimental data (labeled as solid circles) are from Ref. [18] for

Zr55Cu30Al10Ni5   in at.% (Tg = 680 K). Note that this composition is slightly different

from the one used in the MD calculations. Note, dueDue to the high loading rates in the

MD simulation, the higher hardness from calculations may reflect the time-dependent

behavior of the system. Experimental measurables, such as the pileup index [19], have

been be used to verify the computer simulation. The comparison between experiment and

simulation shows a good agreement for indentation depth much less than the film

thickness. For deep indents, the substrate effects make Oliver-Pharr method inaccurate.

                                                                                   Page 7
(Please describe the comparison in the pileup index between the experiment and

simulation).

      The effective strains are shown in Figure 11 for the half-thickness indentation depth

(labeled as the 0.5H case). The displacement loading rate was 16.7 m/s (Please add the

unit). Note that the substrate, appearinged as a regular lattice, has a thickness of 4 Å.

Atomic strains can be calculated from the atom positions at a given time via a discrete

deformation gradient tensor [20]. The effective strains are calculated computed with the

von-Mises-type formula. Radial shear bands (dark regions extending from the indents)

can be observed. The yellow regions are of high strain, where plastic flows occur. Other

dark spots in the film are residual strains, resulting from the deposition. It can be seen

that increasing loading rates causes larger plastic-flow regions. A larger plastic zone

indicates less reaction forces that the zone can provide. Hence, the hardness decreases

with the loading-rate increases, consistent with the experiment [18] (Please give

references on the experiments). The connections between shear transformation zones

(STZ’s) and the atomic shear banding can be understood as that at the beginning of the

indentation, STZs may be activated at the ‘weak spots’ (defined as regions with atoms

loosely packed from the deposition) around the indent with some loading, and embryonic

shear bands may form afterwards due to time-dependent properties or continuous loading.

With increases of the loading, embryonic shear bands may propagate, and form shear

bands eventually. However, the original ‘weak spots’ where first shear transformations

took place may become a part in the plastic-flow regions due to further loading. Moreover,

during the propagation of shear bands, other ‘weak spots’ in the material may go through

the shear transformation when the effective strain reaches a critical value on the order of   Formatted: Font color: Black


0.01 or smaller (the dark regions in Figure 11)--------.                                      Formatted: Font color: Black


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4. Applications

      In addition to the MEMS applications, some TFMG applications have been

explored recently. With the deposition of a 200-nm thick Zr47Cu31Al13Ni9 TFMG, the

fatigue life of the 316L stainless steel is increased by 30 times, while the fatigue limit is

elevated by 30%, as shown in Figure 12 [5], depending on the maximum stress applied to

the steel. This is the first demonstration that confirms the TFMG has a similar property to

that of conventional hard coating materials (e.g.,         TiN) for the fatigue property

improvements. Such property improvements by TFMG are attributed to many factors,

including the high strength, ductile in a thin- film form, compressive residual stress, good

adhesion between the substrate and film to impede the crack initiation and propagation.

The smooth surface after the TFMG coating (4.81 nm vs. 2.55 nm of uncoated and coated

surface roughness, respectively) is also thought to reduce the nucleation sites for crack

initiation on the surface.                                                                      Formatted: Font color: Black


      Unlike copper and its alloys, brass and bronze, whichthat are naturally

antimicrobial materials, the TFMGs are found to be useful for the potential antimicrobial

application by exhibiting much better hydrophobic property due to the amorphous surface

nature. For instance, the wetting angles of the TFMG-coatinged and 304 stainless steel

substrates are 92° and 46°, respectively. Antimicrobial activity test results further reveal

that the Zr-based TFMG exhibits beneficial antimicrobial effects on some microbes, such

as Escherichia coli and Pseudomonas aeruginosa, as shown in Figure 13. Therefore, the           Formatted: Font color: Black


TFMG is promising for improving the antimicrobial properties of substrates in the

medical application. In addition, the TFMG similar to the 304 stainless steel possessing

better corrosion resistance without any localized pitting corrosion after the polarization

                                                                                       Page 9
test (Figure 14). Moreover, the AC impedance test result reveals that the impedance value

of TFMG is superior to that of 316L stainless steel (Figure 15), implying that the TFMG

has a better corrosion resistance owing to its amorphous state.



Conclusions

      In this paper, we have reviewed and presented some important results obtained

from the thin film metallic glasses. Based on the results presented, the metallic glasses in

the thin film form are considered to be potentially useful for their exceptional mechanical

and physical properties. Since the present extent of research in this field is not

considerable as compared to those in the bulk form, there remains a great deal of work to

be done for the better understanding and widespread application of this material.

                                                                                               Formatted: Font: 12 pt


                                                                                               Formatted: Font: 22 pt
Please kindly add a conclusion section!
Acknowledgements

                                                                                               Formatted: Font color: Black
       Many hard-working students and research associates are gratefully acknowledged

for their contributions. This work is supported by National Science Council of Republic

                                                                                               Formatted: Font color: Black
of China, Taiwan, under NSC 98-2221-E-011-037-MY3, 98-2221-E-006-131-MY3 and                   Formatted: Font color: Black

                                                                                               Formatted: Font color: Black
96-2218-E-110-001. PKL would like to acknowledge the financial support of the                  Formatted: Font: Times New Roman, Font
                                                                                               color: Black
                                                                                               Formatted: Font: Times New Roman
National Science Foundation: (1) the Division of the Design, Manufacture, and Industrial

Innovation Program, under DMI-9724476, (2) the Division of Civil, Mechanical,

Manufacture, and Innovation Program, under CMMI-0900271, (3) the Materials World

                                                                                     Page 10
Network Program, under DMR-00909037, (4) the Combined Research-Curriculum

                                                                                             Formatted: Font: Times New Roman
Development (CRCD) Programs, under EEC-9527527 and EEC-0203415, (5) the                      Formatted: Font: Times New Roman
                                                                                             Formatted: Font: Times New Roman
Integrative Graduate Education and Research Training (IGERT) Program, under                  Formatted: Font: Times New Roman


DGE-9987548, (6) the International Materials Institutes (IMI) Program, under

DMR-0231320, and (7) the Major Research Instrumentation (MRI) Program, under

DMR-0421219, to The University of Tennessee, Knoxville, with Dr. D. Durham, Dr. C. V.

Cooper, Dr. A. Ardell, Ms. M. Poats, Dr. C. J. Van Hartesveldt, Dr. J. Giordan, Dr. Dr. D.

Dutta, Dr. W. Jennings, Dr. L. Goldberg, Dr. C. Huber, and Dr. C. R. Bouldin as Program

Directors, respectively.

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                                                                                             space between Asian text and numbers
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References
1. M.W. Chen, Annu. Rev. Mater. Res. 38 (2008), p.445
2. J.C. Huang, J.P. Chu, J.S.C. Jang, Intermetallics 17 (2009),p. 973                        Formatted: German (Germany)

3. Y. Liu, S. Hata, K. Wada and A. Shimokohbe, Proceedings of the 14th IEEE                  Formatted: Font color: Black, German
                                                                                             (Germany)
    International Conference on Micro Electro and Mechanical Systems; Interlaken,            Formatted: Font color: Black
    Switzerland, (2001).
4. J. P. Chu, C. T. Liu, T. Mahalingam, S. F. Wang, M. J. O’Keefe, B. Johnson and C.
    H. Kuo, Phys. Rev. B 69 (2004), p.113410.
5. C. L. Chiang, J. P. Chu, F. X. Liu, P. K. Liaw and R. A. Buchanan, Appl. Phys.
    Lett., 88 (2006), p. 131902.
6. F. X. Liu, P. K. Liaw, W. H. Jiang, C. L. Chiang, Y. F. Gao, Y. F. Guan, J. P. Chu
    and P. D. Rack, Mater. Mater. Sci. Eng. A 468–470 (2007), p.246.                         Formatted: Font color: Black

7. C. J. Chen, J. C. Huang, Y. H. Lai, H. S. Chou, L. W. Chang, X. H. Du, J. P. Chu,
    and T. G. Nieh, J. Alloys Compounds, 483 (2009), p. 337.                                 Formatted: Font color: Black

8. H. S. Chou, J. C. Huang, Y. H. Lai, L. W. Chang, X. H. Du, J. P. Chu, and T. G.
    Nieh, J. Alloys Compounds, 483 (2009), p. 341.                                           Formatted: Font color: Black

9. H. S. Chou, J. C. Huang, L. W. Chang, and T. G. Nieh, Appl. Phys. Lett., 93 (2008),       Formatted: Font color: Black
                                                                                             Formatted: Font color: Black
    p. 191901.
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10. J. P. Chu, C.T. Lo, Y. K. Fang and B. S. Han, Appl. Phys. Lett. 88 (2006), p.
    012510.
11. J.P. Chu, JOM, 61 (2009), p. 72.
12. J. P. Chu, S. F. Wang, S. J. Lee, and C. W. Chang, J. Appl. Phys. 88 (2000), p. 6086.    Formatted: Font color: Black

13. R. B. Schwarz and W. L. Johnson, Phys. Rev. Lett., 51 (1983), p. 415.
14. M. C. Liu, J. C. Huang, H. S. Chou, Y. H. Lai, and T. G. Nieh, Scripta Mater., 61
    (2009), p. 840.
15. H. C. Lin, J. G. Chang, S. P. Ju, C. C. Hwang, P. Roy. Soc. A, 461 (2005), p. 3977.
16. F. Cleri and V. Rosato, Phys. Rev. B, 48 (1993), p. 22.
17. C. A. Schuh and T. G. Nieh, Acta Mater., 51 (2003), p. 87.
18. V. Keryvin, K. E. Prasad, Y. Gueguen, J. Sanglebœuf, and U. Ramamurty, Philos.
    Mag., 88 (2008), p. 1773.
19. F.X. Liu, Y.F. Gao, and P.K. Liaw, Metall. Mater. Trans. A, 39 (2008), p. 1862.          Formatted: Font color: Black

20. P. M. Gullett, M. F. Horstemeyer, M. I. Baskes, H. Fang, Model. Simul. Mater. Sci.       Formatted: Font color: Black

    and Eng., 16 (2007), p. 01500.




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List of figure captions
Figure 1 XRD pattern of the Zr-based TFMG with 1-μm thickness [6].
Figure 2 A pPlane-view bright-field transmission electron microscopy (TEM) image of
         the Zr-based TFMG (Zr61Al7.5Ni10Cul7.5Si4 Please kindly give the composition)
         with a selected area diffraction pattern revealing a homogeneous amorphous
         matrix with dispersed nanocrystallites.
Figure 3 Typical X-ray diffraction patterns for the binary (a) Zu-Cu , and (b) Mg-Cu thin
         films by co-sputtering of elemental targets [7,8].
Figure 4 Plane-view TEM micrographs and diffraction patterns of the Zr-based TFMG
         (Zr47Cu31Al13Ni9) in (a) as-deposited and annealed conditions at (b) 650, (c) 750,
         (d) 800, and (e) 850 K. The circled regions indicate the locations for obtaining
         the diffraction patterns [4].                                                          Formatted: Font color: Black

Figure 5 Variations of the electrical resistivity and hardness of a Zr-based TFMG
         (Zr47Cu31Al13Ni9please kindly give the composition) with the annealing
         temperature. A differential scanning calorimeter DSC (Please kindly spell out
         DSC.) thermogram is included for comparison [4].
                                                                                                Formatted: Font color: Black
Figure 6 SEM micrograph of a micropillar prepared from a Cu-based TFMG (Please
         kindly give the composition.Cu51Zr42Al4Ti3) annealed at 723K in ΔT and                 Formatted: Font color: Black
         deformed under a strain rate of 1×10-3 s-1.                                            Formatted: Font color: Black
Figure 7 Micropillars: (a) Zr-based TFMG (Zr45Cu55) (Please kindly give the                     Formatted: Font color: Black
         composition.) on the top, originally 550 nm in height, compressed to ~ 280 nm
         (or 50 - 55% compression strains), with a thick Zr underlayer. (b) Zr-based
         TFMG remains basically un-deformed, with a soft Cu underlayer heavily
         deformed [14].
Figure 8 Molecular-dynamics model (200 thousand atoms), obtained from sputter-
         deposition simulations, for studying the indentation behavior of the Zr-based
         metallic-glass filmTFMG (Zr47Cu31Al13Ni9Please give the composition),
         indented with a diamond conical tip. A pileup around the indent is observed due
         to the homogeneous flow.
Figure 9 Indentation load-displacement curves at various temperatures for the
         Zr47Cu31Al13Ni9 TFMG from the 40Å-thick MD model. A negative force
         indicates the adhesion between the film and indenter during unloading.
Figure 10 Hardness vs. temperature verification between the simulation and experiment.
                                                                                                Formatted: Font: 18 pt
         (Please    give references on the experiments).
Figure 11 Atomic strain at the indentation depth of a half of the film thickness (labeled as
        the 0.5H case). The displacement loading rate was 16.7 m/s. Shear- banding
        patterns can be observed around the indent.
                                                                                                Formatted: Font color: Black
Figure 12 Stress versus fatigue life cycle for 316L stainless steel with and without the
        Zr-based TFMG (Zr47Cu31Al13Ni9Please give the composition). Arrows indicate             Formatted: Font color: Black
        the run-out data without the failure [5].
Figure 13 Microbes/sample- area ratio as a function of the incubation time for different
        microbes grown on a Mueller-HintonM-H agar plate (Please define M and H).
                                                                                      Page 13
        Escherichia coli (▲), Staphylococcus aureus (□), Pseudomonas aeruginosa (●),
                                   ),
        Acinetobacter baumannii (◇ and Candida albicans (★   ).Please make the figure
        better
Figure 14 Analysis results of Ppolarization curves of 316L stainless steel and TFMGs
        based on ZrCuAlNiV, and ZrTiAlNiV. Please make the figure better                   Formatted: Font color: Black

Figure 15 AC impedance test results of 316L stainless steel and two TFMGs based on
        ZrCuAlNiV and ZrTiAlNiV.
                                                                                           Formatted: Font color: Black




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Figure 1 XRD pattern of the Zr-based TFMG with 1μm thickness [6].




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Figure 2 Plane-view bright-field transmission electron microscopy (TEM) image of the
Zr-based TFMG (Zr61Al7.5Ni10Cul7.5Si4 Please kindly give the composition) with a
selected area diffraction pattern revealing a homogeneous amorphous matrix with
dispersed nanocrystallites.




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       Co-sputtering                                                                                                                         Formatted: Font color: Black
       ZrCu Thin Films                       Unit: W
                                                                                                                                             Formatted: Font color: Black




                                                            Intensity (Arbitraty units)
                                                                                          Mg17.7Cu82.3
                                       Zr300 Cu100

                                       Zr250 Cu150                                        Mg23.5Cu76.5


                                       Zr250 Cu100
                                                                                          Mg40.4Cu59.6
                                       Zr200 Cu150
                                                                                          Mg61.9Cu38.1
                                       Zr200 Cu100

      20        30            40        50             60                         20          25   30    35   40   45   50   55   60
                         2 (degree)                                                                          2
Figure 3 Typical X-ray diffraction patterns for the binary (a) Zu-Cu , and (b) Mg-Cu thin
films by co-sputtering of elemental targets [7,8].




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                                                                                              Formatted: Font color: Black
                              As-deposited            6 50 K
                                                                                              Formatted: Font color: Black




                                 7 5 0K               8 00 K




                                 8 50 K

                                                               Major Spots:
                                                                Cubic Zr2Ni


                                                               Rings:
                                                                Cubic and
                                                                Tetragonal
                                                                Zr2Ni


                      50 nm



Figure 4 Plane-view TEM micrographs and diffraction patterns of the Zr-based TFMG
(Zr47Cu31Al13Ni9) (Please give the composition) in (a) as-deposited and annealed
conditions at (b) 650, (c) 750, (d) 800, and (e) 850 K. The circled regions indicate the
locations for obtaining the diffraction patterns [4].                                         Formatted: Font color: Black




                                                                                    Page 18
                                   Scanning Temperature (K) in DSC
                        25         500   600    700   800    900     1000
                                                                        1200

                             (a)                                        1100

                                                                        1000

                                                                        900

                                                                        800

                                                                        700
                             (b)
                                                                        600
                   70




                   60        (c)


                   50




                   40                                                   0
                      25    500  600    700   800     900            1000
                 As-Deposited   Annealing Temperature (K)

Figure 5 Variations of the electrical resistivity and hardness of a Zr-based TFMG
(Zr47Cu31Al13Ni9) with the annealing temperature. A differential scanning calorimeter
thermogram is included for comparison [4].Variations of electrical resistivity and
hardness of Zr-based TFMG (Please give the composition) with the annealing
temperature. The DSC (Please spell it out) thermogram is included for comparison [4].




                                                                                 Page 19
Figure 6 SEM micrograph of a micropillar prepared from a Cu-based TFMG                     Formatted: Font color: Black

(Cu51Zr42Al4Ti3) annealed at 723K in ΔT and deformed under a strain rate of 1×10-3         Formatted: Font color: Black

s-1SEM micrograph of a micropillar prepared from Cu-based TFMG (Please give the            Formatted: Font color: Black

composition) annealed at 723K in ΔT and deformed under a strain rate of 1×10-3 s-1.        Formatted: Font color: Black


                                                                                           Formatted: Font color: Black




                                                                                 Page 20
                                                                                         Formatted: Font color: Black
      (a)                                  (b)
                                                                                         Formatted: Font color: Black
                                                                                         Formatted: Font color: Black
                                                                                         Formatted: Font color: Black




                                                                    800 nm
Figure 7 Micropillars: (a) Zr-based TFMG (Zr45Cu55Please give the composition) on the    Formatted: Font color: Black

top, originally 550 nm in height, compressed to ~ 280 nm (or 50 - 55% compression        Formatted: Font color: Black
                                                                                         Formatted: Font color: Black, Subscript
strains), with a thick Zr underlayer. (b) Zr-based TFMG remains basically un-deformed,
                                                                                         Formatted: Font color: Black
with a soft Cu underlayer heavily deformed [14].
                                                                                         Formatted: Font color: Black, Subscript
                                                                                         Formatted: Font color: Black




                                                                               Page 21
Figure 8 Molecular-dynamics model (200 thousand atoms), obtained from
sputter-deposition simulations, for studying the indentation behavior of the Zr-based
TFMG (Zr47Cu31Al13Ni9), indented with a diamond conical tip. A pileup around the
indent is observed due to the homogeneous flowobtained from sputter- deposition
simulations, for studying the indentation behavior of the Zr-based metallic-glass film
(Please give the composition), indented with a diamond conical tip. A pileup around the
indent is observed due to the homogeneous flow.




                                                                                Page 22
Figure 9 Indentation load-displacement curves at various temperatures for the
Zr47Cu31Al13Ni9 TFMG from the 40Å-thick MD model. A negative force indicates the
adhesion between the film and indenter during unloading.




                                                                          Page 23
                           9
                                             Zr Cu Al Ni film
                                               47    31   13   9
                                          Hardness from indentation
                           8
           Hardness, GPa




                                                             MD
                           7
                                                    dH/dT = - 2.03 MPa/K

                           6


                           5          Experimental
                                   dH/dT = - 2.07 MPa/K
                           4
                               0   100 200 300 400 500 600 700 800
                                           Temperature (K)

Figure 10 Hardness vs. temperature verification between simulation and experiment.
                                                                                     Formatted: Font: 18 pt
(Please   give references on the experiment).                                        Formatted: Font: 18 pt




                                                                           Page 24
Figure 11 Atomic strain at the indentation depth of a half of the film thickness (labeled as
the 0.5H case). The displacement loading rate was 16.7 m/s. Shear- banding patterns can
be observed around the indent.
                                                                                               Formatted: Font color: Black




                                                                                     Page 25
                                                                                               Formatted: Font color: Black
                                                                                               Formatted: Font color: Black




Figure 12 Stress versus fatigue life cycle for 316L stainless steel with and without the
Zr-based TFMG (Zr47Cu31Al13Ni9)(Please give the composition). Arrows indicate the              Formatted: Font color: Black

run-out data without the failure [5].




                                                                                     Page 26
                                                                                                                 Formatted: Font color: Black
                                                                                                                 Formatted: Font color: Black
                                                     14
                       Microbes/ Sample area Ratio       - - - - : with thin film coating
                                                     12 : 304 stainless steel substrate

                                                     10

                                                      8

                                                      6

                                                      4

                                                      2

                                                      0

                                                          0 10 20 30 40 50 60 70 80 90 100
                                                                          Time (hrs)

Figure 13 Microbes/sample-area ratio as a function of the incubation time for different
microbes grown on a Mueller-Hintonagar plateMicrobes/sample area ratio as a function
of the incubation time for different microbes grown on M-H agar plate (Please define M
and H). Escherichia coli (▲), Staphylococcus aureus (□), Pseudomonas aeruginosa (●),
                             ),                        ).
Acinetobacter baumannii (◇ and Candida albicans (★ Please make the figure better.




                                                                                                       Page 27
                                  2.0

                                  1.5
               Potential (VSCE)




                                  1.0
                                                 ZrCuAlNiV
                                  0.5

                                  0.0                                     ZrTiAlNiV


                                  -0.5                                     361L


                                  -1.0
                                         1E-8 1E-7 1E-6 1E-5 1E-4 1E-3         0.01

                                                 Current Density(A/cm2)



Figure 14 Analysis results of Ppolarization curves of 316L stainless steel and TFMGs            Formatted: Font color: Black

based on ZrCuAlNiV , and ZrTiAlNiV. Please make the figure better.                              Formatted: Font color: Black




                                                                                      Page 28
                        -5000
                                           316L
                                           (ZrTiAlNi-Nanocomposite)
                        -4000              (ZrCuAlNi-Nanomultilayer2)
              Z"(ohm)




                        -3000


                        -2000


                        -1000


                           0
                                0   1000   2000     3000      4000      5000
                                             Z'(ohm)



Figure 15 AC impedance test results of 316L stainless steel and two TFMGs based on
ZrCuAlNiV and ZrTiAlNiV.




                                                                               Page 29

				
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