La_(1-x)M_xFe_yCo_(1-y)O_3型复合氧化物(M=Sr,Ba)的合成、结构及电性能

PREPARATION,STRUCTURE AND ELECTRIC PROPERTY OF La_(1-x)M_xFe_yCo_(1-y)O_3(M=Sr,Ba)

钙钛矿型的稀土与过渡金属复合氧化物(ABO_3)及部分稀土为碱土金属置换的A_(1-x)M_xBO_3型复合物在最近20年来研究较多,并在催化气敏,超导等方面取得了良好进展。但对A_(1-x)M_xB_(1-y)N_yO_3型复合物却研究甚少。本文合成了一系列的La_(1-x)M_xFe_yCo_(1-y)O_3(M=Sr或Ba)钙钛矿型复合氧化物,研究了它们组成与电性的变化规律。

La_(1-x)M_xFe_yCo_(1-y)O_3(M=Sr,Ba,x=0.1～0.9,y=0.1～0.9) have been prepared. The crystal of La_(0.7)Sr_(0.3)Fe_yCo_(1-y)O_3(y=0.1,0. 3) is rbombohedral. The crystal of other compounds is cubic. The lattice parameters of La_(1-x)M_xFe_yCo_(1-y)O_3 increase with increasing the yvalue. The lattice parameters of La_(1-x)Sr_xFe_(0.7)Co_(0.3)O_3 decrease with the increase of the x value, but that of La_(1-x)Ba_xFe_(0.7)Co_(0.3)O_3 increase with the increase of the x value. All the compounds are semiconductors. Their resistivities increase with increasing the y value when x=0.3; decrease with increasing the x value when y=0. 7 and x=0. 1～0. 5; and increase with increasing the x value when y=0.7 and x=0.5～0. 9.