Grain‐orientation‐engineered PMN‐10PT ceramics for electrocaloric applications

Abstract

The electrical properties of ferroelectric materials depend on their crystal orientations. The 〈001〉 and 〈111〉 textured 0.90Pb(Mg1/3Nb2/3)O3–0.10PbTiO3 (PMN‐10PT) ceramics were synthesized using a template grain growth method and conventional solid sintering process. The Lotgering factors of the 〈001〉 and 〈111〉 textured PMN‐10PT ceramics with 5% anisotropic BaTiO3 (BT) precursors were 95% and 87%, respectively. The influence of grain orientation direction on dielectric properties was investigated, revealing that the permittivity of textured PMN‐10PT ceramics (εr〈001〉 = 12200, εr〈111〉 = 11800) was lower than that of random ceramics (εr = 18700). Electrocaloric (EC) responses of the random and textured samples were analyzed using an indirect polarization‐deduced method based on Maxwell's equations. When the applied field was 50 kV cm−1, the 〈111〉 textured ceramics exhibited an enhanced adiabatic temperature change of 1.30 K, which was 20% higher than that of the random samples. In addition, the EC performance of the 〈111〉 oriented samples was significantly improved compared to that of the 〈001〉 oriented ones. This work characterizes the grain‐orientation‐dependent EC responses in the PMN‐PT system, which would be a promising approach to EC response improvement in ferroelectric ceramics.