Magnetization Process of Atacamite: A Case of Weakly Coupled S=1/2 Sawtooth Chains

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 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.

Automated summary

The mineral atacamite Cu2Cl(OH)(3) was studied experimentally and theoretically, revealing a complex evolution of magnetic order with the possibility of a magnetization plateau under the influence of a magnetic field. Theoretical approaches suggest that the magnetization process in atacamite involves a field-driven canting of a 3D network of weakly coupled sawtooth chains, leading to the formation of giant magnetic moments.