Magnetic structure of azurite above the 1/3 magnetization plateau

TL;DR

This study investigates the magnetic structure of azurite above the 1/3 magnetization plateau using high-field NMR, revealing a transverse antiferromagnetic order rather than incommensurate order.

Contribution

It provides new insights into the magnetic ordering in azurite above the 1/3 plateau, challenging previous expectations of incommensurate order.

Findings

Spectral splitting incompatible with incommensurate order

Spectra consistent with transverse canted antiferromagnetic order

Enhanced understanding of magnetic phases in azurite

Abstract

The transition from the 1/3 magnetization plateau towards the saturation magnetization in azurite has been studied by low-temperature, high-magnetic-field, high-frequency proton nuclear magnetic resonance (NMR). The observed symmetrical splitting of the NMR spectra is incompatible with the longitudinal incommensurate order appearing when the longitudinal correlation function becomes dominant over the transverse one, which is the expected framework for the existence of the 2/3 magnetization plateau. The spectra are rather interpreted in terms of a more standard transverse antiferromagnetic (canted) order.