Magnetic properties of a metal-organic antiferromagnet on a distorted honeycomb lattice

TL;DR

This study investigates the magnetic behavior of a metal-organic antiferromagnet on a distorted honeycomb lattice at high temperatures, revealing how its properties can be modeled by a modified spin-wave theory.

Contribution

It provides the first detailed analysis of the magnetic properties of Mn-based metal-organic antiferromagnets on a distorted honeycomb lattice using a modified spin-wave approach.

Findings

Magnetic susceptibility and magnetization data are well explained by the model.

The exchange couplings are approximately J2 ≈ 2J1 ≈ 1.8K.

The model accounts for the absence of spontaneous staggered magnetization at finite temperatures.

Abstract

For temperatures T well above the ordering temperature T*=3.0+-0.2K the magnetic properties of the metal-organic material Mn[C10H6(OH)(COO)]2x2H20 built from Mn^2+ ions and 3-hydroxy-2-naphthoic anions can be described by a S=5/2 quantum antiferromagnet on a distorted honeycomb lattice with two different nearest neighbor exchange couplings J2 \approx 2J1 \approx 1.8K. Measurements of the magnetization M(H,T) as a function of a uniform external field H and of the uniform zero field susceptibility \chi(T) are explained within the framework of a modified spin-wave approach which takes into account the absence of a spontaneous staggered magnetization at finite temperatures.