Phase transition of Pb(Yb1/2Nb1/2)O-3 as the Ba2+ substituting in A-site

Abstract

The phase transition behaviors of Pb(1-x)Bax(Yb1/2Nb1/2)O-3 [Pb1-xBaxYN] solid solution in the composition range, 0 less than or equal to x less than or equal to 0.60, have been investigated by the X-ray diffraction, permittivity, E-P hysteresis loop and TEM measurements. At room temperature, Pb(Yb1/2Nb1/2)O-3 (PYN) displays a phase transition from paraelectric - antiferroelectric to paraelectric - relaxor with an intervening ferroelectric phase which may vary with the Ba2+ concentration. This change coincides with the disappearance of Pb2+ antiparallel displacement and oxygen octahedral tilting mode. Especially, the Ba2+ concentration x = 0.14 defines a boundary between the normal paraelectric-antiferroelectric and the relaxor paraelectric-relaxor transition behavior. Then, the phase diagram of Pb1-xBaxYN solid solution system (0 less than or equal to x less than or equal to 0.60) is presented.