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

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 ΔW=(1/E)(Δσ)2, where E is the elastic modulus, and Δσ the change in stress. The displacement of the magnetization D=Man(H,σ)-M(H,σ) decays with W according to dD/dW=-ξD, where ξ is the decay coefficient. Solving this equation gives,Man(H,σ)-M(H,σ)=[(Man(H, σ)-M(H,σ0)]exp[(-ξ/E)(Δσ)2], which can be rewritten in terms of the change in magnetization with stress ΔM(H,σ,σ0) the magnetomechanical effect,ΔM(H,σ,σ0)=[Man(H,σ)-M(H, σ)]{1-exp[(-ξ/E)(Δσ)2]}. The stress dependent anhysteretic Man(H,σ) can then be determined from the unstressed anhysteretic through the addition of the extra effective field term Hσ: Hσ=(3/2)(σ/μ0)(dλ/dM) so that Man(H,σ)=Man(H + Hσ). Through the use of the last three equations it is possible to describe the changes in magnetization