Fully self-consistent calculations of magnetic structure within non-collinear Alexander-Anderson model

An implementation of the non-collinear Alexander-Anderson model for itinerant electrons in magnetic systems is presented where self-consistency is reached for specified directions of the magnetic moments. This is achieved by means of Lagrange multipliers and a variational principle for determining the transverse and longitudinal components of the magnetic moments as well as the average number of d-electrons using direct optimisation. Various optimisation algorithms are compared and the limited memory Broyden-Fletcher-Goldfarb-Shanno algorithm is found to give the best performance. An application to antiferromagnetic Cr crystal is presented where spin-dynamics and curvature of the energy surface are calculated to compare results obtained with and without the constraints on the orientation of the magnetic moments.

Keywords

itinerant magnetism, Alexander-Anderson model, non-stationary configurations, constraints, EXCHANGE INTERACTIONS, ENERGY, STATES, WAVE, METALS

DOI

10.17586/2220-8054-2020-11-1-65-77

Citation

Ivanov , A , Bessarab , P F , Jonsson , H & Uzdin , V M 2020 , ' Fully self-consistent calculations of magnetic structure within non-collinear Alexander-Anderson model ' , Nanosystems: Physics, Chemistry, Mathematics , vol. 11 , no. 1 , pp. 65-77 . https://doi.org/10.17586/2220-8054-2020-11-1-65-77

Permanent link to this item

https://urn.fi/URN:NBN:fi:aalto-202203282653

Collections

[article-cris] Perustieteiden korkeakoulu / SCI

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