NaCuMoO_4(OH) as a Candidate Frustrated J_1-J_2 Chain Quantum Magnet

TL;DR

This study identifies NaCuMoO_4(OH) as a promising quasi-one-dimensional J_1-J_2 chain quantum magnet, providing experimental estimates of exchange interactions and exploring its magnetic properties, including high-field magnetization behavior.

Contribution

The paper demonstrates that NaCuMoO_4(OH) is a suitable model compound for studying frustrated J_1-J_2 chain magnetism, with detailed experimental characterization and theoretical analysis.

Findings

Estimated exchange interactions: J_1 = -51 K, J_2 = 36 K.

High-field magnetization saturates above 26 T.

No clear evidence of a spin nematic state observed.

Abstract

In a frustrated J_1-J_2 chain with the nearest-neighbor ferromagnetic interaction J_1 and the next-nearest-neighbor antiferromagnetic interaction J_2, novel magnetic states such as a spin-nematic state are theoretically expected. However, they have been rarely examined in experiments because of the difficulty in obtaining suitable model compounds. We show here that the quasi-one-dimensional antiferromagnet NaCuMoO_4(OH), which comprises edge-sharing CuO_2 chains, is a good candidate J_1-J_2 chain antiferromagnet. The exchange interactions are estimated as J_1 = - 51 K and J_2 = 36 K by comparing the magnetic susceptibility, heat capacity, and magnetization data with the data obtained using calculations by the exact diagonalization method. High-field magnetization measurements at 1.3 K show a saturation above 26 T with little evidence of a spin nematic state expected just below the saturation field, which is probably due to smearing effects caused by thermal fluctuations and the polycrystalline nature of the sample.