G 96 Gusev, A. I. Ordered Phases of Lithium Nickelite Li1 – x – zNi1 + xO2 / A. I. Gusev // JETP Letters. - 2004. - vol. 79, № 4. - С. 148-154 : il. - Bibliogr. : p. 153-154 (16 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): НИКЕЛИТ ЛИТИЯ -- ФАЗЫ УПОРЯДОЧЕННЫЕ Аннотация: A symmetry analysis of ordering in lithium nickelite Li1 – x – zNi1 + xO2 (Li1 – x – z hyNi1 + xO2) was performed with regard to the substitution of Li and Ni atoms and the occurrence of structural vacancies h in the metal sublattice. For all the ordered phases, the ray of the Lifshitz {k9} star is present in the order–disorder transition channel. This ray determines the consecutive alternation of atomic planes filled with only Ni atoms or only Li atoms and vacancies in the direction. It was shown that the rhombohedral ordered LiNiO2 phase is formed in the defect-free lithium nickelite, whereas a family of three monoclinic Li3 hNi4O8 (C2/m space group) and Li2 hNi3O6 (C2/m and C2 space groups) superstructures arises as the concentration of structural vacancies increases. For all the superstructures, the order–disorder phase-transition channels were determined and the distribution functions of Li and Ni atoms have been calculated. The long-range order parameters describing each superstructure were found as functions of the Li1 – x – zNi1 + xO2 composition |