DISCONTINUOUS SCALING OF HYSTERESIS LOSSES

We study the dependence of hysteresis loop area A on the frequency OMEGA and amplitude H of the driving field for several mean-field treatments of the kinetic Ising model. An unusual discontinuous double-power-law scaling behavior is found in all cases. In the low-frequency regime, it is found that A - A0 approximately H-2/3OMEGA2/3G(L) (OMEGA/H(gamma)), where A0 is the zero-frequency value of the loop area, G(L) is a scaling function, and gamma is a model-dependent exponent. In the high-frequency regime, the loop area itself scales with frequency and amplitude as A approximately H(alpha)OMEGA-1, where alpha is also a model-dependent exponent. The transition between these extremes is sharp and can be characterized by an amplitude-dependent critical frequency. We also note differences in behavior above and below the critical ordering temperature T(C).