High dielectric constant in (1-x)SrTiO3/xCuO composite ceramics

Semiconductive secondary phase CuO was introduced into SrTiO3 ceramic matrix to yield dielectric composite ceramics with high dielectric constant. The dense composite ceramics could be obtained by sintering at 1050 degrees C in air for 3 h, in which the co-presence of SrTiO3 and CuO/Cu2O was confirmed. The dielectric constant of the present composite ceramics increased firstly and then decreased with increasing the content of CuO, and the highest dielectric constant was obtained at x=0.4. There were steps and peaks on the curves of dielectric constant vs temperature and dielectric loss vs temperature, respectively, and the peak temperatures of dielectric loss indicated the Debye-type relaxation.