Magnetic Composite Materials and Arbitrary $B$-$H$ Relationships

This theoretical study addresses fabricating composite conducting materials with an effective arbitrary B-H relationship in the quasi-static field approximation, exhibiting new magnetic properties. The experimental results demonstrate the possibility of having linear artificial structures with negative effective magnetic permeability. The equivalent circuital model confirms the theoretical and experimental analysis. In particular, following the circuital approach we show how to obtain linear and nonlinear materials that exhibit circular B-H relationships at specific frequencies. Results of a previous experimental analysis aimed at discussing the operative meaning of the measurement of magnetism in composite materials are reported for completeness together with a description of the new conjectured prototypes. Finally, we advance some preliminary discussion on the possibility of defining composite conducting materials that exhibit arbitrary B-H loci symmetrical with respect to the H-axis, for which it is possible to observe wave-like solutions for an electromagnetic field diffusing into the material. This merits further exploration.