Magnetic Moments by gegeshandong


									      The Maglab Presents:
        Magnetic Moments
                         Carlos R. Villa
National High Magnetic Field Laboratory
NHMFL Overview
   One of three national labs in the Southeast U.S.
   One of nine high magnetic field labs in the world
       Only one in western hemisphere
       Largest and highest powered in the world
Center for Integrating
Research & Learning
   Educational component of NHMFL’s grant
   RET programs
       6 weeks
       $3600 stipend
       REU also available
   K-12 education outreach
       9,000 students visited this school year
   Professional development
       Workshops and conferences
Magnet Review
                   Gauss
                       Measurement of magnetic
                       Named for Carl Friedrich
                   Tesla
                       Measurement of larger
                        magnetic fields
                       Named for Nikola Tesla
                       10,000 Gauss = 1 Tesla
Magnetic Metals
   Not all metals are magnetic
   3 Are naturally magnetic
       Iron
       Nickel
       Cobalt
   Exceptions to the rule
       Gadolinium
           Must be frozen
   Fe(II)Fe(III)2O4
   Naturally magnetic
    igneous rock
   Usually found in
    marine sands and deserts
   Largest US deposit in NY (Adirondacks)
   Lodestone found In Arkansas
       Different crystalline structure
   Motion of electrons create magnetic fields
   In some atoms, spins cancel out
       Pauli exclusion
   Magnetic domains
       In magnets: lined up

   Whenever all electrons spin the same direction: magnetic
    field is produced
Permanent Magnets
   Electrons tend to line up in groups (Domains)
   Domains reinforce other domains
       Turn material magnetic

           Examples: Refrigerator Magnets, Bar Magnets, Magnetite, Horseshoe
            Magnets, Hematite, etc…
   Field can be lost
       Curie Point
       Electric Current
           Degaussing
       Bang It
    Temporary Magnets
   Domains temporarily aligned
   Will keep magnetic field until tampered

       Examples:
           Paperclips, scissors, staples, thumb tacks, pins, screwdrivers,
            refrigerator door, car doors, etc…
           Anything that is magnetic, but will not keep its field
Viewing Field Lines
   Field viewers
       Box photo frames
   Iron filings
       Use with paper
       Clean-up can be a mess
Drawing Field Lines
   Seeing fields
       Bar magnet
       As many compasses as
Create A Compass
   Magnetize an item      Allow it to float
                               Must turn freely
                                   Needle
                                   Petri dish
                                   Coffee stirrer
                                   Water
                                   Permanent magnet
Electricity and Magnetism
   The two are so closely related

   Where there is electricity, there is a magnetic field
   Where there is a magnetic field, electricity can be created
Creating Magnetism From Electricity
   Electricity is the movement of electrons
   Electrons flow in one direction
   This alignment of electrons creates a magnetic field
       Similar to electrons lining up in a permanent magnet
       So every wire carrying electricity has a weak magnetic field
        around it (Try it)
   Coiling the wire concentrates the magnetic field
    inside the coil
   Materials
       Copper wire
       Iron rod
       Battery

   Extensions:
       2 batteries
         In line?
       Aluminum, wooden rod
         Will they work?
Electromagnets Extensions:
   Right hand rule
       Direction of field
   Poles (Winding direction)
       Use magnaprobe
   Variables:
       Neatness
       Number of winds
       Wire gauge
       Battery strength
       Temperature
Bitter Plates
Bitter Plates
Iron In Our Food
   Iron in cereal
       Total
       Baby food
   Need a strong magnet
       Neodymium
   A special solution of magnetic particles in a colloidal
    suspension whose flow can be controlled by magnets or
    magnetic fields.
                 Make your own:
                 Oil, petri dish, magnet
                     Please be careful
                 Iron filings:
                     Education Innovations
                     Post Apple Scientific
                 Actual ferrofluids available:
                     Carolina Biological
                     Educational Innovations
Cow Magnets
Additional Resources

Stop Faking It: Electricity   Driving Force:The Natural
& Magnetism                   Magic of Magnets
Bill Robertson                James D. Livingston
Additional Resources

       MagLab Alpha; Science, Optics, & You; other curriculum
       MagLab audio slideshows
   RET Program
   K-12 Programs
                         Carlos R. Villa
National High Magnetic Field Laboratory • 850-644-7191

    Thank You

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