PHENOMENOLOGICAL EQUATIONS FOR THE MAGNETIC PROPERTIES OF <font>La</font>0.7-x<font>Nd</font>x<font>Pb</font>0.3<font>MnO</font>3 COMPOUNDS

Polycrystalline single phase oxides, La 0.7-x Nd x Pb 0.3) MnO 3 (0.3≤x≤0.7), have been synthesized by a standard ceramic fabrication method. A phenomenological model is proposed to describe the magnetization process, and to fit the experiment data of hysteresis loops under different composition ratio. The magnetic hysteresis behavior can be modeled by the formula of [Formula: see text]. The resulted model can satisfy the experiment data ranging from 0.005T to 5T. Explanations on the fitting coefficients of these compounds are addressed.