Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
J Phys Condens Matter. 2011 Apr 27;23(16):164206. doi: 10.1088/0953-8984/23/16/164206. Epub 2011 Apr 6.
The jarosites are the most studied examples of kagome antiferromagnets. Research into them has inspired new directions in magnetism, such as the role of the Dzyaloshinsky-Moriya interaction in symmetry breaking, kagome spin ice, and whether spin glass-like phases can exist in the disorder-free limit. This last point is based around the observation of unconventional thermodynamic and kinetic responses in hydronium jarosite, H(3)OFe(3)(SO(4))(2)(OH)(6), that have led to its classification as a 'topological' spin glass, reflecting the defining role that the underlying geometry of the kagome lattice plays in the formation of the spin glass state. In this paper we explore one of the fundamental questions concerning the frustrated magnetism in hydronium jarosite: whether the spin glass phase is the result of chemical disorder and concomitant randomness in the exchange interactions. Confirming previous crystallographic studies, we use elemental analysis to show that the nature of the low temperature magnetic state is not a simple function of chemical disorder and provide evidence to support the hypothesis that anisotropies drive the spin glass transition.
层状氢铁矾是 kagome 反铁磁体中研究得最多的例子。对它们的研究激发了磁学的新方向，如 Dzyaloshinsky-Moriya 相互作用在对称性破缺、kagome 自旋冰以及无无序限制下是否存在自旋玻璃相的作用。最后这一点是基于对水合氢铁矾，H(3)OFe(3)(SO(4))(2)(OH)(6)中非常规热力学和动力学响应的观察，这些观察导致它被归类为“拓扑”自旋玻璃，反映了 kagome 晶格的基础几何形状在自旋玻璃状态形成中所起的决定性作用。在本文中，我们探讨了水合氢铁矾中受挫磁体的一个基本问题：自旋玻璃相是否是化学无序和交换相互作用随机的结果。通过元素分析，我们证实了先前的晶体学研究，表明低温磁状态的性质不是化学无序的简单函数，并提供证据支持各向异性驱动自旋玻璃转变的假设。
