Application of Internal-Stress-Distribution Theory to Δ E Effect, Initial Permeability, and Temperature-Dependent Magnetomechanical Damping

The internal-stress-distribution model of magnetomechanical hysteresis is extended to a calculation of the ΔE effect, the irreversible low-field permeability, and temperature-dependent magnetomechanical damping. The calculation of the strain dependence of the ΔE effect agrees well with experimental results for Fe-7.65% Ge. The model for permeability yields results for the product λσi(λ=magnetostriction, σi=average internal stress) in reasonable agreement with values from the Becker-Kersten model for reversible initial permeability μ0 and coercive force Hc. The temperature-dependent damping observed in Ni by Roberts and Barrand is ascribed to an increase in domain-wall thickness as anistropy decreases. The model gives reasonable agreement with the measured temperature dependence.