Magnetization Process of Atacamite: A Case of Weakly Coupled <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>S</mml:mi><mml:mo>=</mml:mo><mml:mn>1</mml:mn><mml:mo stretchy="false">/</mml:mo><mml:mn>2</mml:mn></mml:math> Sawtooth Chains
L. Heinze, Harald O. Jeschke, I. I. Mazin, Alexandros Metavitsiadis, M. Reehuis, R. Feyerherm, J.-U. Hoffmann, Maciej Bartkowiak, O. Prokhnenko, A. U. B. Wolter, X. X. Ding, Vivien S. Zapf, Carolina Corvalán Moya, Franziska Weickert, M. Jaime, K. C. Rule, Dirk Мenzel, Roser Valentí, Wilhelm Brenig, S. Süllow
Abstract
We present a combined experimental and theoretical study of the mineral atacamite Cu_{2}Cl(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 plateaulike magnetization at about M_{sat}/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.