A dielectric material when reinforced by ferromagnetic species often results in modified dielectric and other properties on interaction between the electric and magnetic fields [1-3]. The ferromagnetic part influences favorably the dielectric part and viceversa in a single united system of a hybrid composite with tunable composite properties. Impedance studies on CrO2 or composites in form of thin films or a powder compact have drawn great attention owing to exotic magnetization response and dielectric relaxation under alternative electromagnetic fields with controlled dielectric power loss [4, 5]. In this chapter, ZrO2 typifies a model dielectric medium for tailoring functional ferromagnetic properties of metal oxides such as CrO2, CoO, spinal ferrites, and so on. When used as filler in forming a composite. Owing to a high magnetic moment (1.92 μB per Cr

4+ at 10 K)6 with nearly 100% spin polarization of the conduction electrons, CrO2 is preferred over other magnetic oxides as an additive to a ZrO2 type of a dielectric host. We report electrical properties of CrO2 modified ZrO2 of a composition

20CrO2-80ZrO2 of a cubic (c) crystal structure in this chapter. Limited CrO2 solubility does not permit designing a still CrO2 rich sample without scarifying the magnetic properties [7].