Effect of Ba0.93Ca0.04La0.03Sn0.1Ti0.9O3 addition on structural and electrical properties of lead-free 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 piezoelectric ceramics

Abstract

The doping of other materials into the structure of BCZT ceramics can improve the electrical properties. The lead-free piezoelectric ceramics in the (1-x)BCZT–xBCLST binary system, where x = 0.00, 0.01, 0.03, 0.05, and 0.07 mol, were synthesized using a two-step mixed oxide method. Initially, pure phases of 0.5Ba(Zr_0.2Ti_0.8)O₃-0.5(Ba_0.7Ca_0.3)TiO₃ (BCZT) and Ba_0.93Ca_0.04La_0.03Sn_0.1Ti_0.9O₃ (BCLST) powders were separately prepared by mixed oxide and conventional solid-state reaction methods. X-ray diffraction patterns and Ti K-edge X-ray Absorption Near-Edge Structure (XANES) spectra revealed structural distortions in BCLST-doped ceramics. The electrical properties including dielectric, piezoelectric, and ferroelectric properties were evaluated. Besides, the dielectric constant and dielectric loss at room temperature of BCZT–BCLST ceramics were enhanced with increasing BCLST content. The dielectric properties at room temperature improved with increasing BCLST concentration from x = 0.00 to x = 0.03 mol, with the maximum dielectric constant rising from 1408 to 2552—an increase of approximately 81 %. The hysteresis P–E loop of BCZT–BCLST ceramics exhibited a slim loop, with a maximum remanent polarization (P_r) of 7.22 μC/cm² observed at x = 0.03 mol. The optimal doping condition for BCLST in BCZT ceramics was found at 0.03 mol, yielding the highest piezoelectric coefficient (d₃₃) of 235 pC/N—an improvement of approximately 9 % compared to the undoped sample (x = 0.00).