Structure and Conductivity of Tetragonal and Rhombohedral Lanthanum Oxyfluoride Compounds
Structure and Conductivity of Tetragonal and Rhombohedral Lanthanum Oxyfluoride Compounds
复制标题
四方晶系和菱方晶系氟氧化镧化合物的结构和电导率
DOI：
10.1149/1.1394126
复制
发表时间：
2000
影响因子：
3.9
通讯作者：
H. P. Chen
中科院分区：
文献类型：
--
作者：
J. Fergus;H. P. Chen
氟氧化镧化合物可以在LaF 3基氧传感器的电极上形成，因此通过这些化合物的传输可以影响传感器的性能。在高温下，氟氧化镧形成立方萤石结构，其在冷却期间排列成四面体或菱形结构。本文报道了具有不同有序结构（四面体和菱面体）和组成（x = 0-0.75）的氟氧化镧（LaO 1 xF 1+2x）化合物的结构和导电性的研究结果。X射线粉末衍射结果表明，四元LaO 1-xF 1+2x中x值在0 ~ 0.43之间。阻抗谱结果表明最小电导率出现在化学计量LaOF组成附近（即，x = 0），其中存在最少的阴离子点缺陷。
Lanthanum oxyfluoride compounds can form on the electrodes of LaF 3 -based oxygen sensors, so transport through these compounds can affect sensor performance. At high temperatures, lanthanum oxyfluoride forms a cubic fluorite structure, which orders into either a tetragonal or rhombohedral structure during cooling. In this paper, results on the structure and conductivity of lanthanum oxyfluoride (LaO 1 x F 1+2x ) compounds with different ordered structures (tetragonal and rhomhohedral) and compositions (x = 0-0.75) are reported. X-ray powder diffraction results indicate that the value of x in tetragonal LaO 1-x F 1+2x ranges from 0 to 0.43. Impedance spectroscopy results indicate that the minimum conductivity occurs near the stoichiometric LaOF composition (i.e., x = 0), where the fewest anion point defects are present.