Ferroelectric, dielectric and pyroelectric properties of Sr and Sn codoped BCZT lead free ceramics

Abstract

The 1 mol.-%Sr and 1 mol.-%Sn codoped (Ba 0?84 Ca 0?15 Sr 0?01 )(Ti 0?90 Zr 0?09 Sn 0?01 )O 3 (BCSTZS) ceramics were synthesised by the normal solid state sintering method. The electric field and temperature dependence of the ferroelectric properties of the BCSTZS ceramics were investigated. Their energy storage density depending on electric field and temperature was determined from the polarisation-electric field (P-E ) hysteresis loops. According to the dielectric analysis, the BCSTZS ceramics experience three-phase transitions upon cooling. At room temperature, the pyroelectric coefficient p calculated from the remnant polarisation-temperature (P r -T ) curve is 1116?7 mC K 21 m 22 , and the figures of merit F d is 18?1 mPa 21/2 , F v is 0?013 m 2 C 21 and F i is 479?3 pm V 21 respectively. The pyroelectric figures of merit exhibit high frequency stability over a wide range from 100 to 2000 Hz, whereas these values vary gradually with the increase in temperature, which deserves further research to improve their stability. The excellent pyroelectric property of the BCSTZS ceramics is considered as correlating with a polymorphic phase transition occurring around room temperature. The present study demonstrates that the lead free BCSTZS ceramics are promising candidate for replacing the lead zirconate titanate based ceramics.

Enhanced dielectric and electrocaloric properties in lead-free rod-like BCZT ceramics

“…Furthermore, BaTiO 3 is a bioceramic material without any toxic or volatile elements, and its properties can be easily tailored by site engineering [14,19]. However, BaTiO 3 exhibits low dielectric properties compared to lead-based materials and its dielectric constant below the Curie temperature (T c = 393 K) rapidly drops due to the tetragonal/cubic phase transition [20,21]. To overcome the drawback, the Ba 1-x Ca x Zr y Ti 1-y O 3 system is engineered by introducing Ca 2+ and Zr 4+ into the crystal lattice of BaTiO 3 , to replace Ba 2+ and Ti 4+ , respectively, with improved dielectric properties due to enhanced relaxor behavior of Ba 1-x Ca x Zr y Ti 1-y O 3 ceramics [22][23][24][25][26].…”

Dielectric and piezoelectric properties of porous lead-free 0.5Ba(Ca0.8Zr0.2)O3-0.5(Ba0.7Ca 0.3)TiO3 ceramics

“…This promising result has attracted increasing scientific interest of the employment of this lead-free ceramics in transducer applications and replacing current lead-based ferroelectrics. To date, the majority of the literature has focused on tailoring the properties of dense BCZT by doping [5,6], texturing [7,8] and optimising the processing conditions [9,10] to increase its Curie temperature (Tc) or further improving its piezoelectric performance in terms of piezoelectric coefficient and permittivity. An effective way to assess the performance and properties of ferroelectric materials for practical piezoelectric and pyroelectric applications is to compare appropriate figures of merit (FoM) which contain combinations of relevant physical properties.…”

Tuning ferroelectricity by manipulating the global and local structure in a lead-free Sr-doped Ba(Ti1-x Snx)O3ceramics

“…Incipient ferroelectric SrTiO 3 (ST) has proven to be an important dopant for improving ferroelectric properties in systems such as PbZr [44][45][46][47][48]. However, very few studies have been devoted to the Sr-doped BTSnx system, and most of them are focused on Sr-doping levels greater than 10%.…”