• Heinze, L.; Jeschke, H.O.; Mazin, I.I.; Metavitsiadis, A.; Reehuis, M.; Feyerherm, R.; Hoffmann, J.U.; Bartkowiak, M.; Prokhnenko, O.; Wolter, A.U.B.; Ding, X.; Zapf, V.S.; Corvalán Moya, C.; Weickert, F.; Jaime, M.; Rule, K.C.; Menzel, D.; Valentí, R.; Brenig, W.; Süllow, S.: Magnetization Process of Atacamite: A Case of Weakly Coupled S=1/2 Sawtooth Chains. Physical Review Letters 126 (2021), p. 207201/1-7

10.1103/physrevlett.126.207201
Open Access Version

Abstract:
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 plateaulike 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.