Spin-liquid-like state in a spin-1/2 square-lattice antiferromagnet perovskite induced by d<sup>10</sup>-d<sup>0</sup> cation mixing.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 29540711.
- Also identified by DOI 10.1038/s41467-018-03435-1 and PMC identifier 5852160.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
A quantum spin liquid state has long been predicted to arise in spin-1/2 Heisenberg square-lattice antiferromagnets at the boundary region between Néel (nearest-neighbor interaction dominates) and columnar (next-nearest-neighbor interaction dominates) antiferromagnetic order. However, there are no known compounds in this region. Here we use d<sup>10</sup>-d<sup>0</sup> cation mixing to tune the magnetic interactions on the square lattice while simultaneously introducing disorder. We find spin-liquid-like behavior in the double perovskite Sr<sub>2</sub>Cu(Te<sub>0.5</sub>W<sub>0.5</sub>)O<sub>6</sub>, where the isostructural end phases Sr<sub>2</sub>CuTeO<sub>6</sub> and Sr<sub>2</sub>CuWO<sub>6</sub> are Néel and columnar type antiferromagnets, respectively. We show that magnetism in Sr<sub>2</sub>Cu(Te<sub>0.5</sub>W<sub>0.5</sub>)O<sub>6</sub> is entirely dynamic down to 19 mK. Additionally, we observe at low temperatures for Sr<sub>2</sub>Cu(Te<sub>0.5</sub>W<sub>0.5</sub>)O<sub>6</sub>-similar to several spin liquid candidates-a plateau in muon spin relaxation rate and a strong T-linear dependence in specific heat. Our observations for Sr<sub>2</sub>Cu(Te<sub>0.5</sub>W<sub>0.5</sub>)O<sub>6</sub> highlight the role of disorder in addition to magnetic frustration in spin liquid physics.