Magnetization Step in Spatially Distorted Heisenberg Kagome Antiferromagnets

Abstract

Motivated by a recent experiment on volborthite, a typical spin-$1/2$ antiferromagnet with a kagomé lattice structure, we study the magnetization process of a classical Heisenberg model on a spatially distorted kagomé lattice using the Monte Carlo (MC) method. We find a distortion-induced magnetization step at low temperatures and low magnetic fields. The magnitude of this step is given by $\Delta m_z=\left|1-\alpha \right|/3\alpha$ at zero temperature, where $\alpha$ denotes the spatial anisotropy in exchange constants. The magnetization step signals a first-order transition at low temperatures, between two phases distinguished by distinct and well-developed short-range spin correlations, one characterized by spin alignment of a local $120^{\circ }$ structure with a $\sqrt{3}\times \sqrt{3}$ period, and the other by a partially spin-flopped structure. We point out the relevance of our results to the unconventional steps observed in volborthite.

4 pages, 4 figures

References in corpus (4)

• Spin-1/2 Kagome Like Lattice in Volborthite Cu3V2O7(OH)2-H2O
• Field induced transitions in a kagome antiferromagnet
• Magnetization Process of the S=1 and 1/2 Uniform and Distorted Kagome Heisenberg Antiferromagnets
• Magnetization "Steps" on a Kagome Lattice in Volborthite

Cited by in corpus (5)

• One-Third Magnetization Plateau with a Preceding Novel Phase in Volborthite
• Quantum Magnetism in Minerals
• Collapse of Ferrimagnetism in Two-Dimensional Heisenberg Antiferromagnet due to Frustration
• Heterogeneous spin state in the field-induced phase of volborthite as seen via 51V nuclear magnetic resonance
• Distorted Kagome Lattice Generated by a Unique Orbital Arrangement in the Copper Mineral KCu3As2O7(OH)3