Ferroelectric, piezoelectric, pyroelectric and Raman spectroscopy studies on BaTi0.9(Fe1/2Nb1/2)0.1O3 ceramic

The hysteresis, piezoelectric and pyroelectric properties were measured in the temperature range near the ferroelectric–paraelectric phase transition. The BaTi0.9(Fe1/2Nb1/2)0.1O3 ceramic exhibits typical ferroelectric P –E hysteresis behavior with a remanant polarization, Pr, of about 7.52 μC/cm2 detected at 155 K. The electromechanical properties of this composition were measured using the resonance method. The ceramic provides high piezoelectric performance at the temperature of transition (Tmax = 216 K): the piezoelectric constant is d31 = 140 pC/N and the electromechanical coupling factor was kP = 22%. The pyroelectric study confirms the dielectric and ferroelectric measurements. The pyroelectric coefficient is about 125 nC/cm2 K at Tmax. Raman spectra of BaTi0.9(Fe1/2Nb1/2)0.1O3 ceramic were taken at various temperatures and measured over the wave number range from 150 to 1300 cm–1. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)