Magnetics - ENGRI111 MAGNETICS Click to edit Master...

Info iconThis preview shows pages 1–13. Sign up to view the full content.

View Full Document Right Arrow Icon
Click to edit Master subtitle style 10/21/09 ENGRI111 MAGNETICS
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
10/21/09 Examples Cassette tapes Videotapes Hard drives CDs Memory Sticks MP3s Requirements Fidelity Durability
Background image of page 2
10/21/09 Are there any limits? Any limits in the physics/properties of the materials that will slow down the growth of magnetic storage? New approaches to data storage Magnetic storage has new rivals flash memory
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
10/21/09 History Compass invented in China two millenia ago Lodestone – leading stone William Gilbert in 1600 suggested that Earth is a giant magnet Michael Faraday in 1900’s suggested that magnetism and electricity are two sides of a coin Flow of electricity induces a magnetic field A changing magnetic field induces an electrical current Maxwell developed unified theory of electromagnetism in 1880 Magnetic recording became commercial in 1930
Background image of page 4
10/21/09 Magnetic Storage Devices Analog devices – input signal is modulated continuously Digital devices – information is recorded as a sequence of pulses (bits) of 1’s and 0’s Magnetic materials are ideal can be made to point in one or another direction to represent the 1’s and 0’s
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
10/21/09 S N
Background image of page 6
10/21/09 Origin Of Magnetic Properties www.aacg.bham.ac.uk/. ../magnetic_recording.htm Spin Moment Orbital Moment
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
10/21/09 cwx.prenhall.com/. ../media_portfolio/24.htm
Background image of page 8
10/21/09 Ferromagnetic Fe, Ni Antiferromagnetic Cr, Mn Exchange Interaction: acts to align neighboring atoms Parallel: Ferromagnetic
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
10/21/09 Magnetic Domains Magnetic materials lower their energy by dividing into multiple domains Domains are costly – energy associated with their formation H = 0 H > 0
Background image of page 10
10/21/09 Magnetic Domains
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
10/21/09 Domain Walls
Background image of page 12
Image of page 13
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 55

Magnetics - ENGRI111 MAGNETICS Click to edit Master...

This preview shows document pages 1 - 13. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online