Co-existing chiral and collinear phases in a distorted triangular antiferromagnet

TL;DR

This study maps the magnetic phases of a distorted triangular lattice magnet, revealing co-existing chiral and collinear magnetic states with complex phase transformations and order types, supported by comprehensive experimental data.

Contribution

It provides the first detailed experimental phase diagram of KFe(MoO4)2, showing co-existing magnetic subsystems and their distinct behaviors under magnetic fields.

Findings

Identification of two nearly independent magnetic subsystems.

Observation of exotic commensurate-incommensurate phase transformations.

Detection of both 3D and quasi-2D magnetic order in different phases.

Abstract

The entire magnetic phase diagram of the quasi two dimensional (2D) magnet on a distorted triangular lattice KFe(MoO4)2 is outlined by means of magnetization, specific heat, and neutron diffraction measurements. It is found that the spin network breaks down into two almost independent magnetic subsystems. One subsystem is a collinear antiferromagnet that shows a simple spin-flop behavior in applied fields. The other is a helimagnet that instead goes through a series of exotic commensurate-incommensurate phase transformations. In the various phases one observes either true 3D order or quasi-2D order. The experimental findings are compared to theoretical predictions found in literature