Dielectric properties of Ba0.6Sr0.4TiO3-Sr(Ga0.5Ta0.5)O3 solid solutions.

Ba(0.6)Sr(0.4)TiO(3)-Sr(Ga(0.5)Ta(0.5))O(3) solid solutions are prepared by a solid-state reaction method, and their dielectric and tunable characteristics are investigated. The solid solutions with cubic perovskite structures are obtained for compositions of 10-50 mol% Sr(Ga(0.5)Ta(0.5))O(3). It is observed that the addition of Sr(Ga(0.5)Ta(0.5))O(3) into Ba(0.6)Sr(0.4)TiO(3) causes a shift in the phase transition peak to a lower temperature. Ba(0.6)Sr(0.4)TiO(3)-Sr(Ga(0.5)Ta(0.5))O(3) solid solutions exhibit depressed and broadened phase transition peaks, resulting in decreased dielectric constants and dielectric losses at room temperature. With the increase of Sr(Ga(0.5)Ta(0.5))O(3) content, the dielectric constant, loss tangent, and tunability are decreased. 0.9Ba(0.6)Sr(0.4)TiO(3)-0.1Sr(Ga(0.5)Ta(0.5))O(3) has a dielectric constant epsilon = 534 and a tunability of 16% at 100 kHz under 2.63 kV/mm. The dielectric characteristics of Ba(0.6)Sr(0.4)TiO(3)-Sr(Ga(0.5)Ta(0.5))O(3) ceramics at microwave frequencies are also evaluated.