Refining the Spin Hamiltonian in the Spin-1/2 Kagome Lattice Antiferromagnet ZnCu[subscript 3](OH)[subscript 6]Cl[subscript 2] Using Single Crystals

We report thermodynamic measurements of the S=1/2 kagome lattice antiferromagnet ZnCu[subscript 3](OH)[subscript 6]Cl[subscript 2], a promising candidate system with a spin-liquid ground state. Using single crystal samples, the magnetic susceptibility both perpendicular and parallel to the kagome pl...

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Bibliographic Details
Main Authors: Han, Tianheng, Chu, Shaoyan, Lee, Young S.
Other Authors: Massachusetts Institute of Technology. Department of Materials Science and Engineering
Format: Article
Language:en_US
Published: American Physical Society 2012
Online Access:http://hdl.handle.net/1721.1/71622
https://orcid.org/0000-0002-7022-8313
Description
Summary:We report thermodynamic measurements of the S=1/2 kagome lattice antiferromagnet ZnCu[subscript 3](OH)[subscript 6]Cl[subscript 2], a promising candidate system with a spin-liquid ground state. Using single crystal samples, the magnetic susceptibility both perpendicular and parallel to the kagome plane has been measured. A small, temperature-dependent anisotropy has been observed, where χ[subscript z]/χ[subscript p]>1 at high temperatures and χ[subscript z]/χ[subscript p]<1 at low temperatures. Fits of the high-temperature data to a Curie-Weiss model also reveal an anisotropy. By comparing with theoretical calculations, the presence of a small easy-axis exchange anisotropy can be deduced as the primary perturbation to the dominant Heisenberg nearest neighbor interaction. These results have great bearing on the interpretation of theoretical calculations based on the kagome Heisenberg antiferromagnet model to the experiments on ZnCu[subscript 3](OH)[subscript 6]Cl[subscript 2].