Journal of Materials Science, Vol.51, No.7, 3454-3462, 2016
Ferroelectric phase changes and electrocaloric effects in Ba(Zr0.1Ti0.9)(1-x) Sn (x) O-3 ceramics solid solution
The effect of tin (Sn) incorporation in lead-free Ba(Zr0.1Ti0.9)O-3 ceramics was investigated. Single phases with perovskite structure were identified using X-ray diffraction analysis. Dielectric permittivity and pyroelectric current measurements carried out versus temperature revealed ferroelectric-to-paraelectric structural phase transitions showing intermediate ferroelectric-to-ferroelectric sequence anomalies for low Sn-content compounds. Electrocaloric effects were highlighted by recording P-E hysteresis loops as function of temperature and the electrocaloric temperature change a dagger T = 0.2 K was evaluated under 8.7 kV cm(-1) applied electric field. Electrocaloric responsivity of 0.23 K mm kV(-1) near Curie temperature remained almost constant until x = 0.075 before decreasing for compounds with x a parts per thousand yen 0.1. Basing on pyroelectric measurement, we highlight the presence of one quadruple point in this system where the simultaneous presence of Zr and Sn in BaTiO3 matrix seems to stabilize ferroelectric and electrocaloric behaviors instead of Sn element alone.