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.
@article{arxiv.1409.1310,
title = {NaCuMoO_4(OH) as a Candidate Frustrated J_1-J_2 Chain Quantum Magnet},
author = {Kazuhiro Nawa and Yoshihiko Okamoto and Akira Matsuo and Koichi Kindo and Yoko Kitahara and Syota Yoshida and Shohei Ikeda and Shigeo Hara and Takahiro Sakurai and Susumu Okubo and Hitoshi Ohta and Zenji Hiroi},
journal= {arXiv preprint arXiv:1409.1310},
year = {2014}
}