中文摘要：

采用化学共沉淀法合成制备了Ag掺杂摩尔百分比为0.4的La2/3Ca1/3MnO3∶Ag0.4（LCMO∶Ag0.4）、La2/3Ba1/3MnO3∶Ag0.4（LBMO∶Ag0.4）多晶复合材料,通过XRD和R-T分别对两种材料的结构和性能进行测试分析。实验结果表明：所得样品均为正交晶系钙钛矿结构;LCMO∶Ag0.4的金属-绝缘转变温度（Tp=280.2 K）比LBMO∶Ag0.4要高（Tp=256.8 K）;LCMO∶Ag0.4样品的电阻值比LBMO∶Ag0.4要小两个数量级;LCMO∶Ag0.4的TCR最大值为28%,要远远高于LBMO∶Ag0.4的TCR最大值（0.5%）。

英文摘要：

La2/3Ca1/3MnO3∶Ag0.4（LCMO∶Ag0.4） and La2/3Ba1/3MnO3∶Ag0.4（LBMO∶Ag0.4） composite was prepared successfully by co-precipitation method.The microstructure and performance of La2/3Ca1/3MnO3 ∶Ag0.4 and La2/3Ba1/3MnO3 ∶Ag0.4 were investigated by X-ray diffraction and R-T measurement.The results show that,the metal-insulation transition temperature（Tp） of LCMO∶Ag0.4 at 280.2 K is higher than LBMO∶Ag0.4 sample at 256.8 K.The resistivity of LCMO∶Ag0.4 is lower 2 orders than LBMO∶Ag0.4 sample.The temperature coefficient of resistance（TCR） of LCMO∶Ag0.4 is 28%,which is higher than LBMO∶Ag0.4 sample as 0.5%.