Anisotropy-driven spin glass transition in the kagome antiferromagnet hydronium jarosite, (H₃O)Fe₃(SO₄)₂(OH)₆

Abstract

Highly frustrated systems have degenerate ground states that lead to novel properties. In magnetism the consequences of frustration underpin exotic and technologically important effects, such as high temperature superconductivity, colossal magnetoresistance, and the anomalous Hall effect. One of the enduring mysteries of highly frustrated magnetism is why certain experimental systems have a spin glass transition that is not determined by the strength of the dominant magnetic interactions. In this article we show that the spin glass transition in the kagome antiferromagnet hydronium jarosite arises from a coherent anisotropic distortion driven by solvation effects during synthesis. This finding could simplify treatment of the complex spin glass dynamics and has implications far beyond magnetism, as spin glasses provide important models for the out-of-equilibrium dynamics in other frustrated systems.