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Title: The incommensurate magnetic structure of a tetragonal antiferromagnet with antisymmetric exchange

Abstract

Analysis of the incommensurate magnetic structure that emerges for two coexisting types of the antisymmetric Dzyaloshinski-Moriya exchange interaction (the weakly ferromagnetic component of vector D along the tetragonal axis and the helicoidal component distributed in the tetragonal plane) is carried out for the first time for a tetragonal antiferromagnet. The helicoidal component for each pair of interacting spins has a 2D distribution; its direction in the tetragonal plane depends on the direction of the exchange bond in each pair. The Lifshits invariant of the Ginzburg-Landau functional is obtained, which is responsible for the formation of an incommensurate magnetic structure for such a distribution. It is shown in the mean field approximation that the incommensurate magnetic structure that forms in this case is a nonlinear double helicoid with a modulation vector lying in the tetragonal plane and with a varying angle between the polarization planes of quasi-antiferromagnetic sublattices. The ground state of the magnet is degenerate in the orientation of the modulation vector in the tetragonal plane. The rate of variation in the orientations of moments in the polarization planes passing through the tetragonal axis is controlled by the angle between the directions of the moments and the tetragonal axis. Themore » local weakly ferromagnetic moment remaining in the polarization plane varies in magnitude and sign. The relation between the orientations of the modulation and polarization vectors is derived for the cases of simple and inversion tetragonal axes in the space symmetry group of the crystal.« less

Authors:
 [1]
  1. Russian Academy of Sciences, Kirenskii Institute of Physics, Siberian Branch (Russian Federation)
Publication Date:
OSTI Identifier:
21443643
Resource Type:
Journal Article
Journal Name:
Journal of Experimental and Theoretical Physics
Additional Journal Information:
Journal Volume: 109; Journal Issue: 6; Other Information: DOI: 10.1134/S1063776109120097; Copyright (c) 2009 Pleiades Publishing, Ltd.; Journal ID: ISSN 1063-7761
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 36 MATERIALS SCIENCE; ANTIFERROMAGNETIC MATERIALS; ANTIFERROMAGNETISM; APPROXIMATIONS; CRYSTALS; EXCHANGE INTERACTIONS; FERROMAGNETISM; GINZBURG-LANDAU THEORY; MEAN-FIELD THEORY; MODULATION; NONLINEAR PROBLEMS; ORIENTATION; POLARIZATION; SPIN; TETRAGONAL LATTICES; ANGULAR MOMENTUM; CALCULATION METHODS; CRYSTAL LATTICES; CRYSTAL STRUCTURE; INTERACTIONS; MAGNETIC MATERIALS; MAGNETISM; MATERIALS; PARTICLE PROPERTIES

Citation Formats

Martynov, S N. The incommensurate magnetic structure of a tetragonal antiferromagnet with antisymmetric exchange. United States: N. p., 2009. Web. doi:10.1134/S1063776109120097.
Martynov, S N. The incommensurate magnetic structure of a tetragonal antiferromagnet with antisymmetric exchange. United States. https://doi.org/10.1134/S1063776109120097
Martynov, S N. Tue . "The incommensurate magnetic structure of a tetragonal antiferromagnet with antisymmetric exchange". United States. https://doi.org/10.1134/S1063776109120097.
@article{osti_21443643,
title = {The incommensurate magnetic structure of a tetragonal antiferromagnet with antisymmetric exchange},
author = {Martynov, S N},
abstractNote = {Analysis of the incommensurate magnetic structure that emerges for two coexisting types of the antisymmetric Dzyaloshinski-Moriya exchange interaction (the weakly ferromagnetic component of vector D along the tetragonal axis and the helicoidal component distributed in the tetragonal plane) is carried out for the first time for a tetragonal antiferromagnet. The helicoidal component for each pair of interacting spins has a 2D distribution; its direction in the tetragonal plane depends on the direction of the exchange bond in each pair. The Lifshits invariant of the Ginzburg-Landau functional is obtained, which is responsible for the formation of an incommensurate magnetic structure for such a distribution. It is shown in the mean field approximation that the incommensurate magnetic structure that forms in this case is a nonlinear double helicoid with a modulation vector lying in the tetragonal plane and with a varying angle between the polarization planes of quasi-antiferromagnetic sublattices. The ground state of the magnet is degenerate in the orientation of the modulation vector in the tetragonal plane. The rate of variation in the orientations of moments in the polarization planes passing through the tetragonal axis is controlled by the angle between the directions of the moments and the tetragonal axis. The local weakly ferromagnetic moment remaining in the polarization plane varies in magnitude and sign. The relation between the orientations of the modulation and polarization vectors is derived for the cases of simple and inversion tetragonal axes in the space symmetry group of the crystal.},
doi = {10.1134/S1063776109120097},
url = {https://www.osti.gov/biblio/21443643}, journal = {Journal of Experimental and Theoretical Physics},
issn = {1063-7761},
number = 6,
volume = 109,
place = {United States},
year = {2009},
month = {12}
}