DISCONTINUOUS SCALING OF HYSTERESIS LOSSES

We study the dependence of hysteresis loop area A on the frequency OME GA and amplitude H of the driving field for several mean-field treatme nts of the kinetic Ising model. An unusual discontinuous double-power- law scaling behavior is found in all cases. In the low-frequency regim e, it is found that A - A0 approximately H-2/3OMEGA2/3G(L) (OMEGA/H(ga mma)), 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 hi gh-frequency regime, the loop area itself scales with frequency and am plitude as A approximately H(alpha)OMEGA-1, where alpha is also a mode l-dependent exponent. The transition between these extremes is sharp a nd can be characterized by an amplitude-dependent critical frequency. We also note differences in behavior above and below the critical orde ring temperature T(C).