Modeling the effects of stress on magnetization in ferromagnetic materials (abstract)

Journal Article · Sun May 15 04:00:00 EDT 1994 · Journal of Applied Physics; (United States)

DOI:https://doi.org/10.1063/1.355634· OSTI ID:7238619

Jiles, D C ^[1]

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1. Ames Laboratory, Iowa State University, Ames, Iowa 50011 (United States)

So far no attempts have been made to quantitatively model the effects of changing stress under constant field. The main principle in this case is the approach of the magnetization to the anhysteretic. The anhysteretic is itself stress dependent, and therefore presents a moving target for the bulk magnetization. The displacement of the bulk magnetization in isotropic media is determined by the elastic energy supplied [Delta][ital W]=(1/[ital E])([Delta][sigma])[sup 2], where [ital E] is the elastic modulus, and [Delta][sigma] the change in stress. The displacement of the magnetization [ital D]=[ital M][sub an]([ital H],[sigma])[minus][ital M]([ital H],[sigma]) decays with [ital W] according to [ital dD]/[ital dW]=[minus][xi][ital D], where [xi] is the decay coefficient. Solving this equation gives,[ital M][sub [ital an]]([ital H],[sigma])[minus][ital M]([ital H],[sigma])=[([ital M][sub [ital an]]([ital H], [sigma])[minus][ital M]([ital H],[sigma][sub 0])]exp[([minus][xi]/[ital E])([Delta][sigma])[sup 2]], which can be rewritten in terms of the change in magnetization with stress [Delta][ital M]([ital H],[sigma],[sigma][sub 0]) the magnetomechanical effect,[Delta][ital M]([ital H],[sigma],[sigma][sub 0])=[[ital M][sub [ital an]]([ital H],[sigma])[minus][ital M]([ital H], [sigma])][l brace]1[minus]exp[([minus][xi]/[ital E])([Delta][sigma])[sup 2]][r brace]. The stress dependent anhysteretic [ital M][sub [ital an]]([ital H],[sigma]) can then be determined from the unstressed anhysteretic through the addition of the extra effective field term [ital H][sub [sigma]]: [ital H][sub [sigma]]=(3/2)([sigma]/[mu][sub 0])([ital d][lambda]/[ital dM]) so that [ital M][sub [ital an]]([ital H],[sigma])=[ital M][sub [ital an]]([ital H] + [ital H][sub [sigma]]). Through the use of the last three equations it is possible to describe the changes in magnetization.

• OSTI ID: 7238619
• Journal Information: Journal of Applied Physics; (United States), Journal Name: Journal of Applied Physics; (United States) Vol. 75:10; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

665000* -- Physics of Condensed Matter-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ENERGY
FERROMAGNETIC MATERIALS
MAGNETIC MATERIALS
MAGNETIZATION
MATERIALS
MATHEMATICAL MODELS
STRESSES