掺杂TiO₂的La_2/3Ba_1/3MnO₃电输运与磁电阻特性

掺杂TiO 2 的La 2/3 Ba 1/3 MnO 3 电输运与磁电阻特性 Transport and Magnetoresistance Properties in TiO 2 -Doped La 2/3 Ba 1/3 MnO 3 刘长征 LIU Chang-zheng 1 2 first-author 戴明星 DAI Ming-xing 1 2 周千学 ZHOU Qian-xue 1 2 金磊 JIN Lei 1 2 艾定飞 AI Ding-fei 1 2 武汉大学物理科学与技术学院 武汉大学物理科学与技术学院 School of Physics and Technology, Wuhan University School of Physics and Technology, Wuhan University 武汉大学物理科学与技术学院,湖北,武汉,430072 武汉大学物理科学与技术学院,湖北,武汉,430072 通过固相反应法制备了（1-x）La2/3Ba1/3MnO3+xTiO2（x=0% 5 %）多晶陶瓷样品.实验发现,随着TiO2掺杂量的增加,电阻率明显增大,金属-绝缘相转变温度Tp值下降.通过室温（300K）和低温（78K）下不同磁场的磁电阻计算表明,适量的TiO2掺杂会明显提高材料的磁电阻性能;在1T磁场下,TiO2掺杂量为1%的样品室温磁电阻达到12%,这是未掺杂La2/3Ba1/3MnO3相同条件下的3倍,为磁电阻传感器研究提供了实验依据. (1-x)La 2/3 Ba 1/3 MnO 3 +xTiO 2 （x=0%-5%） polycrystalline ceramic samples were prepared by solid-state-reaction method. It is found that with increasing TiO 2 doping level, the resistivity increases obviously, and the metal-insulator transition temperature T p decreases. The magnetoresistances measured in different magnetic fields at room temperature（300 K） and low temperature （78 K） show that moderate TiO 2 dopant can enhance the magnetoresistance obviously. The magnetoresistance for the sample with 1% TiO 2 dopant in 1T magnetic field reaches 12% at room temperature, which is 3 times larger than undoped La 2/3 Ba 1/3 MnO 3 under the same condition,which provides the experimental proof for the magnetoresistance sensor research. 磁电阻 晶界 电阻率 掺杂 magnetoresistance grain boundary resistivity dopant O482.5 国家自然科学基金资助项目（59972024） 2005-03-01 2021-04-01 3