High- and low-pressure forms of LiTiM2+F6 (M2 = Mn, Fe, Co, and Ni) were prepared by the reaction of LiF, TiF3, and MF2 under conditions of 1.5-7.0 GPa and 700-1200°C. All the low-pressure phases belonged to a trirutile structure. On the other hand, the high-pressure phases crystallized in a Na2SiF6-type structure for M2+ = Mn and a PbSb2O6-type structure for M2+ = Fe, Co, and Ni. According to the Rietveld analysis, it was observed that such structures were basically described as hexagonal close packing of F- ions with cations placed in half of the octahedral sites, but involved a significant difference in cationic proportions at the z = 0 and 1 2 levels. Detailed structure data of high- and low-pressure phases are included in the present paper, and the structural stability of each phase is discussed relative to the synthetic PT conditions.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry