E 27 Effects of Structural Disorder in Lithium Manganite and Titanate Oxides / Yu. G. Chukalkin, A. E. Teplykh, D. G. Kellerman, V. S. Gorshkov // Physics of the Solid State. - 2010. - vol. 52, № 5. - P1006-1009 : il. - Bibliogr. : p. 1009 (11 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): МАНГАНИТ ЛИТИЯ -- ТИТАНАТЫ -- СТЕХИОМЕТРИЯ Аннотация: The structures and magnetic states of stoichiometric lithium manganite LiMn2O4 and manganites and titanates Li1.33Mn1.67O4 and Li1.33Ti1.67O4 with excess lithium in both the initial (as-synthesized) state and after irradiation by fast (Eeff ≥ 1 MeV) neutrons with a fluence of 2 × 1020 cm–2 have been studied using neutron diffraction, X-ray diffraction, and magnetic methods. It has been established that the irradiation brings about a noticeable redistribution of manganese, titanium, and lithium cations over nonequivalent tetrahedral (8a) and octahedral (16d) positions of a spinel lattice. This structural disorder causes a radical change in the physical properties of the materials under study. The charge order existing in the initial LiMn2O4 sample is destroyed. There arises a strong intersublattice indirect exchange interaction Mn(8a)–O–Mn(16d). The disorder is accompanied by the antiferromagnet–ferrimagnet (LiMn2O4) and paramagnet–ferrimagnet (Li1.33Mn1.67O4) magnetic transitions Полный текст |