We present a combined experimental and theoretical study of the mineral atacamite Cu2Cl(OH)3. Density functional theory yields a Hamiltonian describing anisotropic sawtooth chains with weak 3D connections. Experimentally, we fully characterize the antiferromagnetically ordered state. Magnetic order shows a complex evolution with the magnetic field, while, starting at 31.5 T, we observe a plateau-like magnetization at about Msat/2. Based on complementary theoretical approaches, we show that the latter is unrelated to the known magnetization plateau of a sawtooth chain. Instead, we provide evidence that the magnetization process in atacamite is a field-driven canting of a 3D network of weakly coupled sawtooth chains that form giant moments.
@article{arxiv.1904.07820,
title = {Magnetization process of atacamite: a case of weakly coupled $S = 1/2$ sawtooth chains},
author = {L. Heinze and H. O. Jeschke and I. I. Mazin and A. Metavitsiadis and M. Reehuis and R. Feyerherm and J. -U. Hoffmann and M. Bartkowiak and O. Prokhnenko and A. U. B. Wolter and X. Ding and V. S. Zapf and C. Corvalán Moya and F. Weickert and M. Jaime and K. C. Rule and D. Menzel and R. Valentí and W. Brenig and S. Süllow},
journal= {arXiv preprint arXiv:1904.07820},
year = {2021}
}