# Magnetic interactions in the $S = 1/2$ square-lattice antiferromagnets Ba$_2$CuTeO$_6$ and Ba$_2$CuWO$_6$: parent phases of a possible spin liquid

## TL;DR

This study investigates the magnetic interactions in Ba$_2$CuTeO$_6$ and Ba$_2$CuWO$_6$, revealing their frustrated square-lattice antiferromagnetic nature and predicting a spin-liquid-like ground state in their solid solutions.

## Contribution

It provides a combined theoretical and experimental analysis of the magnetic properties of these double perovskites, highlighting the role of orbital hybridisation in their magnetic frustration and potential for spin liquid behavior.

## Key findings

- Ba$_2$CuTeO$_6$ and Ba$_2$CuWO$_6$ are frustrated square-lattice antiferromagnets.
- Differences in orbital hybridisation drive opposing magnetic interactions.
- Predicted spin-liquid-like ground state in Ba$_2$Cu(Te$_{1-x}$W$_x$)O$_6$ solid solutions.

## Abstract

The isostructural double perovskites Ba$_2$CuTeO$_6$ and Ba$_2$CuWO$_6$ are shown by theory and experiment to be frustrated square-lattice antiferromagnets with opposing dominant magnetic interactions. This is driven by differences in orbital hybridisation of Te$^{6+}$ and W$^{6+}$. A spin-liquid-like ground state is predicted for Ba$_2$Cu(Te$_{1-x}$W$_x$)O$_6$ solid solution similar to recent observations in Sr$_2$Cu(Te$_{1-x}$W$_x$)O$_6$.

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Source: https://tomesphere.com/paper/1812.05619