Dielectric and micromechanical studies of barium titanate substituted (1-y)Pb (Zn1/3Nb2/3)O3-yPT ferroelectric ceramics

Abstract

Dielectric studies have been carried out on barium titanate substituted lead zinc niobate ferroelectrics ceramics, (Pb0.88Ba0.12)[(Zn1/3Nb2/3)(0.88)Ti-0.12)]O-3 and (Pb0.8Ba0.2)[(Zn1/3Nb2/3)(0.8)Ti-0.2)]O-3. The dielectric dispersion of the solid solutions has been studied as a function of temperature in the frequency range 100 Hz-1MHz. The temperature variation of the real components of dielectric permittivity (epsilon') at different frequencies shows a diffuse phase transition. Micromechanical studies have been carried on (Pb0.88Ba0.12)[(Zn1/3Nb2/3)(0.88)Ti-0.12)]O-3 and (Pb0.8Ba0.2)[(Zn1/3Nb2/3)(0.8)Ti-0.2)]O-3 by nanoindentation at different loads. Hardness, Young's modulus, elastic energy and total energy have been extracted. It is seen that in case of (Pb0.8Ba0.12)[(Zn1/3Nb2/3)(0.8)Ti-0.2)]O-3, the plastic deformation energy is lower than the other sample, which is due to extra Ti content in B-site. This is also reflected in polarization studies, which confirms that the presence of Ti4+ in B-site brings forth rigidity in Ti-O bond.