An Approach to Modeling and Scaling of Hysteresis in Soft Magnetic   Materials. I Magnetization Curve
  A new mathematical model of hysteresis loop has been derived. Model consists in an extansion of tanh($\cdot$) by extanding the base of exp function into an arbitrary positive number. The presented model is self-similar and invariant with respect to scaling. Scaling of magnetic hysteresis loop has been done using the notion of homogenous function in general sense. 
Krzysztof Z. Sokalski
cond-mat.mtrl-sci