GTBL042-18 GTBL042-Callister-v2 September 13, 2007 13:46

Revised Pages

Chapter 18 Magnetic Properties

Photomicrographs of an iron single

crystal, showing magnetic domains and

their change in shape as a magnetic field

(H) is applied. The magnetization

direction of each domain is indicated by

an arrow. Those domains that are

favorably oriented with the applied field

grow at the expense of the unfavorably

oriented domains. (Photomicrographs

courtesy of General Electric Research

Laboratory.)

WHY STUDY theMagnetic Propertiesof Materials?

An understanding of the mechanism that explains the

permanent magnetic behavior of some materials may

allow us to alter and in some cases tailor the magnetic

properties. For example, in Design Example 18.1 we

note how the behavior of a ceramic magnetic material

may be enhanced by changing its composition.

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