User:Brian P. Josey/Notebook/2010/01/22

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Domain Theory

I managed to finish The Hitchhikers Guide to Magnetism on Wednesday, but I only updated through the the very beginning part of the section on domain theory. This entry will be for that section, and I will cut out the last section from my notes. While it was an interesting read, it had more to do with geology than anything else, and isn't really pertinent to what we are doing, so I will just drop it out.

Domain Theory

Domains are subdivisions of the magnetic material that has its magnetization oriented in a particular direction. A magnetic material can have one, several or very many domains. They are very small, on the order of 1 to 100's microns, but much larger than atomic distances. They were first hinted at, when it was discovered that coercivity and remanence vary with the size of a grain.

My reading had a very good explanation on how domains can form.

  • Some important acronyms are:
    • SPM- superparamagnetic
    • SD- single domain
    • PSD- pseudo-single domain
    • MD- multidomain