Dielectric properties of bismuth doped Ba1-xSrxTiO3 ceramics

The dielectric properties of bismuth (5 at.%) doped Ba1- xSrxTiO3 (x = 0, 0 .2, 0.4, 0.6 and 0.8) ceramics are investigated. Bi doping significantly de creases the dielectric permittivity maximum of ferroelectric-paraelectric p hase transition of Ba1-xSrxTiO3 solid solutions and shifts the ferroelectri c-paraelectric phase transition temperature to lower temperatures for the x = 0, 0.2. 0.4 and 0.6 compositions but to higher temperature for the x = 0 .8 composition. Bi doped BaTiO3 still exhibits normal ferroelectric charact eristic while a relaxer behavior was observed in Bi doped Ba1-xSrxTiO3 and the degree of the diffuseness and the relaxation increases as x increases. A random electric field is suggested to be responsible for the relaxer beha vior observations. (C) 2001 Elsevier Science Ltd. All rights reserved.