Pyroelectric properties of 91.5Na0.5Bi0.5TiO3–8.5K0.5Bi0.5TiO3lead-free single crystal

Bo Zhang; Renbing Sun; Fang Wang; Tangfu Feng; Pengna Zhang; Haosu Luo

doi:10.1142/S2010135X21500235

Abstract

The dielectric and pyroelectric performances of 91.5

{Na}_{0.5}

{Bi}_{0.5}

TiO₃–8.5

K_{0.5}

{Bi}_{0.5}

TiO₃ lead-free single crystal were investigated. The depolarization temperature of the crystal is about 153

^{\circ}

C. Among the <001>, <110>, and <111> crystallographic orientations, the <111>-oriented crystal possesses the highest pyroelectric coefficient and the largest figures of merit, and the values of

p

,

F_{v}

, and

F_{d}

are 5.63×10

^{- 4}

C/m² •K, 0.06 m²/C, and 21.5

μ

Pa

^{- 1 / 2}

for the <111>-oriented crystal at room temperature. The

F_{d}

and

F_{v}

exhibit weak frequency dependence in the range of 100–300 Hz. With the increase of the temperature, the value of

p

increases, while the value of

F_{v}

decreases from 18

^{\circ}

C to 103

^{\circ}

C.The dielectric and pyroelectric performances of 91.5

{Na}_{0.5}

{Bi}_{0.5}