Measurements of output-dependent Preisach functions

The interiors of hysteresis loops were examined for commercial recording tape samples of γ-Fe₂O₃ and Co-modified γ-Fe₂O₃. It was found that the minor loops did not satisfy the congruency condition of the classical Preisach model. Since both the moving model and the product model are capable of describing minor loops whose height varies with the magnetization, they were used to analyze this data. It was found that the results were consistent with the expectations of the moving model and not with the product model. An identification method for the moving parameter is given. Two models for the reversible component of the magnetization that are compatible with the moving model are presented