Fizika Nizkikh Temperatur: Volume 45, Number 12 (December 2019), p. 1485-1492    ( to contents , go back )

Localized magnetic non-uniformities in an antiferromagnet with a system of dislocations

V.E. Kireev1 and B.A. Ivanov1,2

1Institute of Magnetism, NASU, 36-B Vernadskii Ave., Kiev 03142, Ukraine

2National Taras Shevchenko University of Kiev, Kiev 03127, Ukraine
E-mail: bor.a.ivanov@gmail.com

Received Jule 24, 2019, published online October 25, 2019

Abstract

For antiferromagnets, lattice dislocations are the origin of the singular line in the field of the antiferromagnetic vector l, common to disclinations in the field of vector-director for nematic liquid crystals. Single atomic dislocation produces non-localized state, spin disclination. It is shown that “compensated” system of dislocations, closed dislocation loop in three-dimensional (3D) AFM or pair of point dislocations in two-dimensional (2D) AFM, produces localized spin non-uniformity, common to soliton. For isotropic or easy-plane AFM the form is ellipsoidal or circular in 3D or 2D cases, accordingly. The geometry of lattice defect and soliton is significantly different, for example, the planar lattice defect (dislocation loop) produces almost-spherical 3D spin non-uniformity. In the presence of inplane anisotropy, the domain wall ending on the dislocation line (points) is formed.

Key words: antiferromagnet, sublattice, dislocation, spin disclination.

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