Gv. Shilov et al., Crystal growth and crystal structures of the layered ionic conductors - sodium lithium titanium oxides, INT J INORG, 2(5), 2000, pp. 443-449
Single crystals of four structure types have been grown from melts of the N
a2O-Li2O-TiO2 system. Structures of two of them have been determined by the
single-crystal X-ray diffraction. The both structures comprise brucite-lik
e octahedral (Ti,Li)O-2 layers with random Li/Ti distribution. One of them,
(Na0.73Li0.24)(Li0.32Ti0.68)O-2, is rhombohedral (alpha -NaFeO2 type), whe
reas the other, Na-0.66(Li0.22Ti0.78)O-2, hexagonal containing sodium ions
in trigonal prisms of two kinds with occupancies 0.36(1) and 0.29(3), respe
ctively. One more crystal, (Na,Li)(3)(LiTi2)O-6, is a superlattice of the a
lpha -NaFeO2 type due to Li/Ti ordering. Relationships between the cation-c
ation repulsion, cationic disorder, relative stability of the structure typ
es and their cation transport properties have been discussed. (C) 2000 Else
vier Science Ltd. All rights reserved.