HONG Yuhong, ZHANG Xiaozhen, WU Chunrong, JIANG Yuhua, WANG Yongqing, ZHOU Jian-er

(Key Laboratory of Jiangxi Universities for Inorganic Membrane, School of Materials Science and Engineering,

Jingdezhen Ceramic Institute, Jingdezhen 333403, Jiangxi, China)

Abstract:La_0.8Sr_0.2MnO₃ (LSM)-Al₂O₃ system ceramic materials were prepared by high temperature solid-state sintering techniques. The influences of Al₂O₃ content on the phase composition, microstructure, porosity, bulk density, electric conductivity, and flexural strength of the prepared LSM-Al₂O₃ system conductive ceramics were investigated. X-ray diffraction analysis found complex solid reactions between LSM and Al₂O₃ occurred during the process of heating up to 1400 °C for 2 h, in which different La_1-xSr_xMnO₃ materials and other non-conductive phases were formed. The  increase of Al₂O₃ content in LSM-Al₂O₃ system leads to worse sinterability, increased porosity and greatly reduced electric conductivity. The sample without and with 40% Al₂O₃ shows an electric conductivity of 1508 S/m and 1×10^-5 S/m, respectively. The flexural strength of samples shows obvious increase firstly and then decrease with the increase of Al₂O₃ content. 

Key words:conductive ceramic; lanthanum strontium manganate; alumina; electric conductivity; flexural strength.