La^3＋掺杂对BaTiO3纳米陶瓷微观结构及其性能的影响

Effects on Microstructure and Characteristics of BaTiO3 Nanometer Ceramics by La^3＋-doping

采用sol-gel法制备了La^3＋掺杂BaTiO3纳米陶瓷．用DTA-DTG，XRD，PAT和PIA等对目标产物进行分析测试．研究结果表明，在800℃下煅烧2h得到粒径约为50～70nmBaTiO3纳米粉体，La^3＋的掺杂可以降低BaTiO3纳米晶体的烧结温度并使其晶格发生收缩畸变,当0≤x≤0．2，产生弱束缚电子从而导致电阻率降低；当0．2≤x≤0．4产生钡空穴从而导致电阻率升高．

Ba1-x Lax TiO3 （abbreviated as BLT） nanometer ceramics were prepared by sol-gel process. The samples were investigated by differential thermal analysis and differential thermal gravimetric analysis （DTA DTG）, X-ray diffraction （XRD）, positron annihilation technique （PAT） and precision impedance analysis （PIA）. The results showed that the BaTiO3 nanometer powder with cubic perovskite structure in size of 50-70 nm is obtained at 800 ℃ sintering for 2 h. The doping of La^3＋ resulted in the decreasing of the sintering temperature and the shrinking of the crystal lattice. The doping of La^3＋ induced the declining of the resistivity due to the formation of the weak bound electrons（Ti^4＋ · e^- ） in the range of 0≤x≤0.2 and the rising of the resistivity due to the formation of the barium vacancy （V＂Ba） in the range of 0.2≤x≤0.4.