Electrocaloric effect of alkali co-substituted Sr0.6Ba0.4Nb2O6 ceramics

[摘要] We have investigated the electrocaloric properties of Kthorn and Nathorn co-substituted Sr0.6Ba0.4Nb2O6 (SBN) ceramics using the indirect method. Tetragonal tungsten bronze (K0.5Na0.5)2x(Sr0.6Ba0.4)(5-x)Nb10O30 (KNSBN) with x = 0.24 was synthesized using dual-step sintering. Despite the low amount, K+ and Na+ co-substitution resulted in normal ferroelectric behaviour, showing no significant shift in the dielectric maximum temperature of 111 degrees C with increasing frequency. Maximum electrocaloric temperature change (Delta T) of 0.3 K was observed at an electric field of 30 kV/cm (Delta E) yielding the largest electrocaloric responsivity (Delta T/Delta E) among SBN based ceramics. This relatively large value is in agreement with the larger pyroelectric coefficient of KNSBN compared to SBN based ceramics. (c) 2020 Elsevier B.V. All rights reserved.

[发布日期] 2020-12-05

[关键词] Electrocaloric effect;Strontium barium niobate;Tetragonal tungsten bronze;Cation disorder