Investigation of new magneto-dielectric titania-cobalt ferrite composites

Novel magneto-dielectric cobalt ferrite (CFO)- titania (TO) ceramic composites with composition (100-x)TO-xCFO with x ranging from 20 to 80 wt.% were prepared by conventional solid state reaction. Highly densified composites with two to three phases homogeneously distributed were obtained. The formation of a new ternary compound Fe2CoTi3O10 (FCTO) was observed only in composites having TO/CFO molar ratios equal to or larger than 2.2. The magneto-dielectric ceramic composites obtained can be classified by phases content in different classes with one of the starting CFO and /or TO always present; in the range of high CFO content the formation of CoTiO3 and Fe2O3 was detected. Magnetic permeability, dielectric permittivity (?') and losses (tan ?) were determined and correlated with the molar ratio of the dielectric and magnetic phases in the composites.