Anisotropic magnetic properties of the triangular plane lattice material TmMgGaO4

TL;DR

This study investigates the crystal structure and magnetic behavior of TmMgGaO4, revealing highly anisotropic magnetic properties and frustration effects due to structural disorder and triangular lattice geometry.

Contribution

It provides the first detailed analysis of the anisotropic magnetic properties and disorder effects in TmMgGaO4, a triangular lattice magnetic material.

Findings

Magnetic moments are highly anisotropic, with large moments perpendicular to the planes.

No magnetic ordering observed down to 1.8 K despite antiferromagnetic interactions.

Broad magnetization feature near 2 Tesla at 2 K indicates complex magnetic behavior.

Abstract

The crystal growth, structure, and basic magnetic properties of TmMgGaO4 are reported. The Tm ions are located in a planar triangular lattice consisting of distorted TmO6 octahedra, while the Mg and Ga atoms randomly occupy intermediary bilayers of M-O triangular bipyramids. The Tm ions are positionally disordered. The material displays an antiferromagnetic Curie Weiss theta of ~ -20 -25 K, with no clear ordering visible in the magnetic susceptibility down to 1.8 K; the structure and magnetic properties suggest that ordering of the magnetic moments is frustrated by both structural disorder and the triangular magnetic motif. Single crystal magnetization measurements indicate that the magnetic properties are highly anisotropic, with large moments measured perpendicular to the triangular planes. At 2 K, a broad step-like feature is seen in the field-dependent magnetization perpendicular to the plane on applied field near 2 Tesla.