Elemental analysis and magnetism of hydronium jarosites—model kagome antiferromagnetsand topological spin glasses

Abstract

The jarosites are the most studied examples of kagome antiferromagnets. Research into themhas inspired new directions in magnetism, such as the role of the Dzyaloshinsky–Moriyainteraction in symmetry breaking, kagome spin ice, and whether spin glass-like phases canexist in the disorder-free limit. This last point is based around the observationof unconventional thermodynamic and kinetic responses in hydronium jarosite,H3OFe3(SO4)2(OH)6, that have led to its classification as a ‘topological’ spin glass, reflecting the defining rolethat the underlying geometry of the kagome lattice plays in the formation of the spin glassstate.In this paper we explore one of the fundamental questions concerning the frustratedmagnetism in hydronium jarosite: whether the spin glass phase is the result of chemicaldisorder and concomitant randomness in the exchange interactions. Confirming previouscrystallographic studies, we use elemental analysis to show that the nature of the lowtemperature magnetic state is not a simple function of chemical disorder andprovide evidence to support the hypothesis that anisotropies drive the spin glasstransition.