NaCuMoO4(OH) as a Candidate Frustrated J1–J2 Chain Quantum Magnet

Abstract

In a frustrated J1–J2 chain with the nearest-neighbor ferromagnetic interaction J1 and the next-nearest-neighbor antiferromagnetic interaction J2, 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 NaCuMoO4(OH), which comprises edge-sharing CuO2 chains, is a good candidate J1–J2 chain antiferromagnet. The exchange interactions are estimated as J1 = −51 K and J2 = 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.