Phase Diagram and Impedance Spectroscopy Study of the La0.5+x−yBiyLi0.5−3xTiO3 System

The phase diagram of the system Li2O/La2O3/TiO2/Bi2O3 has been studied. Using powder X-ray diffraction, five distinct areas have been found in the triangle Bi0.5Li0.5TiO3/La2/3TiO3/La0.5Li0.5TiO3. A region of perovskite-like solid solutions was obtained when the bismuth content in the general formula La0.5+x−yBiyLi0.5−3xTiO3 was less than y = 0.10. Two two-phase regions, one of them consisting of a perovskite-like phase and La2Ti2O7, and the other a perovskite-like phase and Li2TiO3, were obtained. One four-phase region, consisting of a perovskite-like phase, Li2TiO3, Bi4Ti3O12 and La4Ti3O12, was also obtained. The fifth area corresponds to the melting of the initial mixtures. The microstructures of these phases were studied by SEM/EDS. The compounds of general formula La0.5+x−yBiyLi0.5−3xTiO3 are ionic conductors. Their ionic conductivity increases when the amount of lithium rises up to x = 0.075, and decreases when the amount of bismuth increases. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)

[1]  E. Suard,et al.  Structural and transport characteristics ofthe LAMOX family of fast oxide-ion conductors, based on lanthanum molybdenumoxide La2Mo2O9 , 2001 .

[2]  P. Lacorre.  The LPS concept, a new way to look at anionic conductors , 2000 .

[3]  M. L. M. Sarrión,et al.  Synthesis, Phase Diagram, and Conductivity Study in a La0.5+x+yLi0.5−3xTi1−3yMn3yO3System , 1998 .

[4]  M. L. M. Sarrión,et al.  Synthesis and electrical properties of the Pr0.5+x+yLi0.5–3xTi1–3yCr3yO3system , 1998 .

[5]  M. Crosnier-Lopez,et al.  Structural and Microstructural Studies of the Series La2/3−xLi3x□1/3−2xTiO3 , 1996 .

[6]  A. West,et al.  Phase diagram, crystal chemistry and lithium ion conductivity in the perovskite-type system Pr0.5+xLi0.5−3xTiO3 , 1996 .

[7]  G. C. Mather,et al.  The Crystal Structures of Li+ Conducting Phases Li0.5-3x RE0.5+x TiO3: RE=Pr,Nd, x≈0.05, from Powder Neutron Diffraction Data , 1996 .

[8]  M. Itoh,et al.  Influences of carrier concentration and site percolation on lithium ion conductivity in perovskite-type oxides , 1996 .

[9]  G. C. Mather,et al.  Crystal structure of the Li+ ion-conducting phases, Li0.5 – 3x Re0.5 +x TiO3: RE = Pr, Nd; x≈ 0.05 , 1995 .

[10]  A. West,et al.  Phase diagrams and crystal chemistry in the Li+ ion conducting perovskites, Li0.5 – 3xRE0.5 +xTiO3 : ReLa, Nd , 1995 .

[11]  H. Kawai,et al.  Lithium Ion Conductivity of A‐Site Deficient Perovskite Solid Solution La0.67 − x Li3x TiO3 , 1994 .

[12]  Liquan Chen,et al.  Candidate compounds with perovskite structure for high lithium ionic conductivity , 1994 .

[13]  Liquan Chen,et al.  High lithium ion conductivity in the perovskite-type compounds Ln12Li12TiO3(Ln=La,Pr,Nd,Sm) , 1994 .

[14]  A. West,et al.  Phase diagrams and stoichiometries of the solid electrolytes, Bi4V2O11: M, M = Co, Cu, Zn, Ca, Sr , 1994 .

[15]  D. Sinclair,et al.  Stoichiometry and stability of bismuth vanadate, Bi4V2O11, solid solutions , 1993 .

[16]  G. Mairesse,et al.  Phase transitions and ionic conductivity in Bi4V2O11 an oxide with a layered structure , 1988 .

[17]  P. Bruce,et al.  A new analysis of ac conductivity data in single crystal β-alumina , 1982 .

[18]  A. Jonscher,et al.  Analysis of the complex impedance data for β-PbF2 , 1978 .

[19]  E. M. Levin,et al.  Polymorphism of Bismuth Sesquioxide. II. Effect of Oxide Additions on the Polymorphism of Bi2O3 , 1964, Journal of research of the National Bureau of Standards. Section A, Physics and chemistry.