Enhancement of pyroelectric properties of lead-free 0.94Na0.5Bi0.5TiO3-0.06BaTiO3 ceramics by La doping

Lead-free 0.94NBT-0.06BT-xLa ceramics at x = 0.0-1.0 (%) were synthesized by a conventional solid-state route. XRD shows that the compositions are at a morphotropic phase boundary where rhombohedral and tetragonal phases coexist. With increasing La3+ content pyroelectric coefficient (p) and figures of merits greatly increase; however, the depolarization temperature (T-d) decreases. p is 7.24 x 10(-4)C.m(-2) degrees C-1 at RT at x = 0.5% and 105.4 x 10(-4)C.m(-2) degrees C-1 at Td at x = 0.2%. F, and F show improvements at RT from 1.12 (x = 0%) to 2.65 (x10(-10) mv(-1)) (x = 0.5%) and from0.021 to 0.048 (m(2).C-1) respectively. F-1, and F-v show a huge increase to 37.6 x 10(-10) mv(-1) and 0.56 m(2) C-1 respectively at Td at x = 0.2%. Fc shows values of 2.10, 2.89, and 2.98 (x10(-9)C cm(-2) C-1) at RTat33,100 and 1000 (Hz) respectively. Giant pyroelectric properties make NBT-0.06BT-xLa at x = 0.2% and 0.5% promising materials for many pyroelectric applications. Crown Copyright (C) 2016 Published by Elsevier Ltd. All rights reserved.