Dielectric and X-Ray Diffraction Studies in Highly Ordered Complex Perovskite Pb(Yb1/2Nb1/2)O3

Dielectric and X-ray diffraction measurements were used to characterize the structural phase transition occurring in antiferroelectric Pb(Yb1/2Nb1/2)O3 compound. Dielectric behavior for ceramics shows a sharp transition with a large temperature hysteresis of about 6°C near transition temperature. The lattice parameters and spontaneous strain have been investigated in the temperature range between 20 and 400°C using X-ray powder diffraction. High temperature X-ray data indicates that the Pb(Yb1/2Nb1/2)O3 undergoes an orthorhombic to cubic phase transition near transition temperature. The temperature dependence of the spontaneous strain is discussed by phenomenological theory.