Magnetic materials with conjugate major loops

This paper considers magnetic materials whose upper (B+) and lower (B−) major loops are conjugate, mapping into each other through reflection through the origin: B±(−H)=−B∓(H). Conjugacy imposes conditions also on the gradients of the major loops, ensures certain combinations of the major loops are either even or odd functions of H, and imposes constraints on Ev, the energy loss per unit volume per cycle. Conjugacy is shown to hold, to a good degree of approximation, for several examples from power steels and ferrites. The bounds on Ev are satisfied by the published experimental data considered, and the properties of the identified even and odd functions of H are discussed.