E 43 Electronic Structure and Magnetic States of Crystalline and Fullerene-Like Forms of Nickel Dichloride NiCl2 / A. N. Enyashin, N. I. Medvedeva, Yu. E. Medvedeva, A. L. Ivanovskii // Physics of the Solid State. - 2005. - Vol. 47, № 3. - P527-530 : il. - Bibliogr. : p. 530 (12 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ДИХЛОРИД НИКЕЛЯ -- ФУЛЛЕРЕНЫ -- ФЕРРОМАГНЕТИКИ -- СТЕХИОМЕТРИЯ Аннотация: The electronic structure and magnetic properties of the crystalline and fullerene-like forms of nickel dichloride NiC² are investigated in the framework of the local spin density functional theory. It is demonstrated that the band gap can be reproduced in the energy band spectrum of the NiCl² compound with inclusion of the magnetic ordering in the calculation of the band structure. The metamagnetic nature of the NiCl² dichloride (i.e., the transition from an antiferromagnetic phase to a ferromagnetic phase in a weak magnetic field) is explained in terms of a small difference (0.025 eV/cell) between the total energies of the ferromagnetic and antiferromagnetic phases. Polyhedral three-shell nanoparticles of the NiCl² compound exhibit magnetic properties (the magnetic moment of nickel lies in the range 2.0–2.3 µβ). For isostructural nanoparticles of the FeCl² dichloride, the magnetic moment of iron is larger and falls in the range 4.2–4.5 µβ, whereas nanoparticles of the CdCl² dichloride are found to be nonmagnetic. The results of analyzing the interatomic interactions indicate that the composition of fullerene-like nanoparticles of the dichlorides under investigation can deviate from the 1 : 2 stoichiometric composition Полный текст |