The magnetic structure of Li2CuO2: from ab initio calculations to macroscopic simulations

TL;DR

This study combines ab initio calculations and macroscopic simulations to analyze the magnetic structure of Li2CuO2, revealing detailed magnetic interactions and a Neel temperature consistent with experimental data.

Contribution

It provides a comprehensive analysis of Li2CuO2's magnetic interactions using ab initio calculations and Monte Carlo simulations, refining previous estimates of interaction ratios.

Findings

First and second neighbor magnetic interactions calculated as -142 K and 22 K.

Interchain interactions are weak and antiferromagnetic.

Monte Carlo simulations yield a Neel temperature aligning with experiments.

Abstract

The magnetic structure of the edge sharing cuprate compound Li2CuO2 has been investigated by means of ab initio electronic structure calculations. The first and second neighbor in-chain magnetic interactions are calculated to be -142 K and 22 K, respectively. The ratio between the two parameters is smaller than suggested previously in the literature. The interchain interactions are antiferromagnetic in nature and of the order of a few Kelvins only. Monte Carlo simulations using the ab initio parameters to define the model Hamiltonian result in a Neel temperature in rather good agreement with experiment. Spin population analysis situate the magnetic moment on the copper and oxygen ions somewhere between the completely localized picture derived from experiment and the more delocalized picture based on local density calculations.