Dimensional crossover of a frustrated distorted kagome Heisenberg Model: Application to FeCrAs

TL;DR

This paper investigates the magnetic behavior of a classical spin model on a distorted kagome lattice inspired by FeCrAs, revealing a complex phase diagram with potential magnetic orders matching experimental observations.

Contribution

It introduces a simple Heisenberg spin model on a distorted kagome lattice coupled to trimers, explaining magnetic phases observed in FeCrAs.

Findings

Identification of a rich phase diagram including a (1/3,1/3,0) magnetic order.

Demonstration of how coupling between kagome spins and trimers influences magnetic states.

Potential explanation for experimental magnetic order in FeCrAs.

Abstract

Motivated by recent experimental work on FeCrAs, we study the magnetic properties of classical spin models on the hexagonal Fe$_2$P/ZrNiAl structure (space group $P{\bar{6}}2m$). When both transition metal/rare earth sites carry magnetic moments, one has alternating distorted kagome and triangular lattice layers. Each point of the triangular lattice lies at the centre of a distorted hexagon and actually corresponds to three isolated magnetic atoms: a "trimer". We show that a simple model consisting of antiferromagnetically correlated Heisenberg spins on the frustrated distorted kagome lattice coupling either ferromagnetically or antiferromagnetically to Heisenberg spins at the average position of a trimer, leads to a rich phase diagram, including the possible selection of a $(1/3,1/3,0)$ magnetic order as may have been seen in FeCrAs.