Investigations of the magnetic structure of the distorted S = 1/2 kagome antiferromagnets ACu3V2O7(OD)2Cl (A = K, Rb, ND4 )

Two-dimensional S=1/2 kagome antiferromanets (KAFMs) are some of the best candidate systems for studies of the novel ground states and exotic, often fractionalized, excitations that characterize quantum spin liquids (QSLs). Away from the isotropic kagome lattice, the ground states of the distorted systems are less well studied despite predictions they host unconventional magnetic order and topological magnetic excitations. Further understanding of these phases is hindered by the limited number of distorted kagome systems which display the highly 2-dimensional magnetic lattice populated by S=1/2 spins. We propose a low-temperature study on WISH of the distorted S=1/2 KAFM series, ACu3V2O7(OD)2Cl A = ND4+, K+, Rb+, to characterise their ordered magnetic ground states. Substitution on the A cation site alters the exchange environment of each material and provides a means to produce different ground state phases. Each material is structurally analogous, with distorted kagome layers of S=1/2 Cu2+ ions well separated by V2O7 units and interstitial ions. Bulk magnetometry data collected on the series hints at variations in their ordered ground states and shows differences in the strength of their antiferromagnetic mean fields. The detailed characterisation of these ordered ground states would help map the phase diagram of the distorted S= 1/2 KAFMs.