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 epsiv = 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.