Ferroelectric-ferromagnetic composite materials

A composite ferroelectric-ferromagnetic material for use as an electrical filter, said material consisting essentially of:

• a first phase of grains of a ferroelectric material and a second phase of grains of a ferromagnetic material wherein the first phase is interconnected to a second phase and so that said ferroelectric and ferromagnetic grains substantially retain their respective discrete electromagnetic properties;
• said composite ferroelectric-ferromagnetic material having a closed porosity ranging from 0 to 3 volume percent of the composite, wherein said composite ferroelectric-ferromagnetic material is suitable for reducing electromagnetic interference of an electrical lead, and said composite having a capacitive loss, which is the imaginary permittivity/real permittivity, of less than 0.1 at one Khz, and said ferromagnetic material is present in about 30 to about 70 percent by volume of the composite and said ferroelectric material is present in about 30 to about 70 percent by volume of the composite, and wherein said ferromagnetic material is a copper-based ferrite, and said ferroelectric material is selected from the group consisting of barium-based and strontium-based materials, wherein said copier-based ferrite is of the AB.sub.2 O.sub.4 type where A is Cu and at least one selected from the group consisting of Mg, Zn, Ni and Mn, and B is primarily Fe, and including MgO in excess of the stoichiometric amount for a AB.sub.2 O.sub.4 compound.