Phase diagrams and crystal chemistry in the Li⁺ion conducting perovskites, Li_{0.5 – 3x}RE_{0.5 +x}TiO₃: ReLa, Nd

Abstract

The stoichiometry, stability and polymorphism of the perovskite-related solid solutions, Lio,-~REo,,+,TiO, : RE = La, Nd, has been studied. For both series, the data are presented in the form of a temperature vs. composition phase diagram. Unit cell data for the different polymorphs (three in the La system, four in the Nd system) are presented, together with data on the composition and thermal history dependence of the lattice parameters. The phase composition and microstructure of selected ceramic samples were analysed by electron microprobe techniques.

Comparison of the electrical properties of the new conductor Pr0.5Bi0.05Li0.35TiO3 prepared by sol–gel and ceramic methods

“…The system RE 0.5+x-y Bi y Li 0.5-3x TiO 3 with RE: La [7] and Pr [8,9] has been reported. The materials were prepared using a ceramic method and showed perovskite-like structure and lithium conductivity.…”

Nanocheckerboard modulations in (NaNd)(MgW)O6

“…The lack of stability for the stoichiometric mixed A-site endmember is strikingly similar to the ͑RE͒ 2/3−x Li 3x TiO 3 ͑RE =Nd,La͒ systems where "͑RELi͒Ti 2 O 6 " is also unstable and cannot be formed without trace amounts of a lithium-rich impurity. 10 In summary, the structure of ͑NaNd͒͑MgW͒O 6 is comprised of ordered domains with a doubled periodicity along both ͑110͒ directions in the a-b plane. Neighboring domains have an antiphase relationship and are separated by twodimensional periodic APB's parallel to the ͕110͖ planes with a 7͑110͒a p repeat.…”

The ion conducting properties of perovskite solid solutions (La 1/2 Li 1/3+X )TiO 3

“…The ionic conductivity growth with vacant site concentration increasing was reported [2,3,5,6]. The same effect was observed when the smaller B-site ion substituted for titanium due to the interatomic bond lengths changes with the B -O bond strengthening and the Li -O bond weakening [4].…”