Open AccessМагнитный фазовый переход в MnSi на основе LSDA+U +SO-расчетов электронной структуры и спин-флуктуационной теории
Author(s) -
А.Г. Волков,
Т.А. Ноговицына,
А.А. Повзнер,
Т.М. Нуретдинов
Publication year - 2018
Publication title -
fizika tverdogo tela
Language(s) - English
Resource type - Journals
eISSN - 1726-7498
pISSN - 0367-3294
DOI - 10.21883/ftt.2018.10.46512.105
Subject(s) - condensed matter physics , paramagnetism , magnetization , magnetic susceptibility , ferromagnetism , physics , superposition principle , phase transition , magnetic structure , spin (aerodynamics) , magnetic field , quantum mechanics , thermodynamics
pin states appearing near the magnetic phase transition in helicoidal ferromagnet MnSi are studied on the basis of the spin-fluctuation theory and the LSDA + U + SO calculations of the electronic structure. The temperature dependence of the uniform magnetic susceptibility is calculated near the magnetic phase transition temperature, and the result agrees well with the experiment. Spin correlators corresponding to various solutions of the equation of magnetic state are determined in the region of the magnetic phase transition expanded in temperature. It is shown that, in this region, a helicoidal short-range order appears in the form of the superposition of left and right spin spirals with stochastic weight coefficients. It is shown that the magnetic susceptibility divergences on the helicoid wave vector at the temperature of disappearance of local magnetization and during the transition to the paramagnetic state.