Lead-free relaxors with“TTB” structure containing either lanthanum or bismuth

TTB-type lead-free relaxor compositions containing either lanthanum or bismuth were studied. Their temperature and frequency dielectric properties were investigated on ceramics. The relaxor characteristics of similar compositions containing either lanthanum or bismuth were compared. The value of Tm, the temperature of the maximum of ε′r, was systematically higher for bismuth samples. The values of ΔTm, the variation of Tm from 102 to 105 Hz, were very high. With a value of Tm near to room temperature, BaBiNb5O15 seems to be a good candidate for environment-friendly applications. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)