Thermoelectric characteristics of textured KSr2Nb5O15 ceramics

Abstract

Effect of crystal anisotropy on thermoelectric properties of textured KSr2Nb5O15 ferroelectric ceramics is studied for the first time. Temperature dependent conductivity and Seebeck coefficient were measured in directions parallel and perpendicular to the c direction. A transition in electrical conduction from semiconductor to metallic behavior was observed at around 610 K. The power factor was remarkably improved depending on measurement directions such that it was 390 mu W/mK(2) in parallel and 283 mu W/mK(2) in perpendicular to the c direction at 1120 K. Textured KSr2Nb5015 ceramics are promising candidates to be used as n-type thermoelectric materials at high temperatures and oxidizing environments. (C) 2015 Elsevier Ltd. All rights reserved.