Electronic and magnetic properties of the 2H-NbS$_2$ intercalated by 3d transition metal atoms

TL;DR

This study investigates the electronic and magnetic properties of 2H-NbS$_2$ intercalated with 3d transition metals Cr, Mn, and Fe, revealing how intercalation influences magnetic anisotropy and magnetic structures, aligning with experimental findings.

Contribution

The paper provides a detailed theoretical analysis of how intercalation with different 3d transition metals alters the magnetic anisotropy and magnetic ordering in 2H-NbS$_2$, including the discovery of a transition from in-plane to out-of-plane easy axis.

Findings

Cr$_{1/3}$NbS$_2$ exhibits easy plane MCA decreasing towards Curie temperature.

Cr and Mn intercalation induce helimagnetic structures along the c axis.

Fe intercalation leads to non-collinear frustrated magnetism without MCA, but strong MCA stabilizes a third-kind magnetic order.

Abstract

The electronic structure and magnetic properties of the 2H-NbS$_2$ compound intercalated by Cr, Mn and Fe, have been investigated by means of the Korringa-Kohn-Rostoker (KKR) method. The calculations demonstrate easy plane magneto-crystalline anisotropy (MCA) of Cr$_{1/3}$NbS$_2$ monotonously decreasing towards the Curie temperature in line with the experimental results. The modification of the electronic structure results in a change of the easy axis from in-plane to out-of-plane. It is shown, that for Cr$_{1/3}$NbS$_2$ and Mn$_{1/3}$NbS$_2$ the in-plane MCA and Dzyaloshinskii-Moriya interactions results in a helimagnetic structure along the hexagonal $c$ axis, following the experimental observations. The negative exchange interactions in the Fe$_{1/3}$NbS$_2$ compound results in a non-collinear frustrated magnetic structure if the MCA is not taken into account. It is shown, however, that a strong MCA along the hexagonal $c$ axis leads to a magnetic ordering referred to as an ordering of the third kind, which was observed experimentally.