K. R. S. Preethi Meher, Rahul Vaish, J. Hou, Dalibor Krsmanovic, R. V. Kumar, K. B. R. Varma
August 17, 2013
Polycrystalline Ca 0.18 Sr 0.226 Ba 0.594 Nb 2 O 6 (CSBN18) was synthesized via the solid-state reaction route. X-ray structural studies confirmed it belonged to the tetragonal tungsten bronze family. Rietveld refinement of the X-ray data has been carried out for CSBN18 where the atomic positions and site occupancy factors for A-sites have been determined. The dielectric properties of CSBN18 ceramic were studied as a function of temperature in the 100 Hz–1 MHz frequency range. The dielectric relaxation followed the Vogel–Fulcher relation wherein E a = 37.4 meV; T f = 131.5 °C and ω 0 = 4.31 × 10 9 rad s −1 . A high pyroelectric coefficient of ∼ 250 μC m −2 .K was obtained around the transition temperature (∼150 °C). This is significantly higher than that reported for polycrystalline Sr x Ba 1-x Nb 2 O 6 (SBN). However, the piezoelectric coefficient ( d 33 ) of the title composition was as low as 6 pC N −1 .