Dielectric properties of (1−x)[0.7PbZrO3·0.3K0.5Bi0.5TiO3]·xSrTiO3 solid solutions in the vicinity of phase transitions

Relaxor behaviour of (1 −x) [0.7PbZrO3–0.3(K0.5Bi0.5)TiO3]–xSrTiO3solid solutions

“…Temperature dependences of ε and ε obtained at various frequencies for compounds under study display a typical behaviour for relaxor FEs (figures 7 and 8). The Cole-Cole plots for compounds with concentration x = 0.7 [10] revealed two relaxation processes near T m supposedly caused by phase and domain boundaries motion inherent for FE crystals [1,4,[19][20][21][22][23][24]. The presence of several dispersion mechanisms in compounds with concentration x = 0.7 is confirmed by several linear parts in the dependence of the characteristic relaxation time τ versus inverse temperature (inset in figure 8).…”

“…To prepare samples of the (1 − x)[0.7PbZrO 3 -0.3(K 0.5 Bi 0.5 ) TiO 3 ]-xSrTiO 3 system (0.0 x 0.7) a two-stage ceramic technology was applied by mixing Bi 2 O 3 , TiO 2 , ZrO 2 , SrO, PbO and K 2 CO 3 powders [10]. The synthesis was performed at 900 ˚C during 3 h and the final firing at 1200-1250 ˚C during 1 h. To limit lead loss from pellets, a PbO-rich atmosphere was maintained by placing PbZrO 3 powder around the pellets during the sintering procedure.…”

“…Among a number of FE solid solutions which could be used for study, we took the (1 − x)[0.7PbZrO 3 -0.3(K 0.5 Bi 0.5 )TiO 3 ]-xSrTiO 3 system. Our choice was based on the following reasons: (i) the dielectric properties of (1 − x)[0.7 PbZrO 3 -0.3(K 0.5 Bi 0.5 )TiO 3 ]-xSrTiO 3 solid solutions have been studied earlier [10]; (ii) these materials are a continuous set of solid solutions; (iii) the phase diagram includes the morphotropic phase boundary; and (iv) the concentration dependence of lattice distortions shows step-like anomalies.…”