Abstract
We present results of and nuclear magnetic resonance (NMR) measurements on , a frustrated pyrochlore magnet with a Curie-Weiss temperature K and intrinsic bond disorder. Below 3.6 K both the and spectra broaden substantially in comparison to higher temperatures accompanied by a considerable reduction (80%) of the NMR signal intensity: This proves a broad quasistatic field distribution. The spin-lattice relaxation rate ) exhibits a peak at 2.9 K already starting to develop below 10 K. We attribute the spin freezing to the presence of bond disorder. This is corroborated by large-scale Monte Carlo simulations of a classical bond-disordered XY model on the pyrochlore lattice. The low freezing temperature, together with the very short magnetic correlation length not captured by the simulations, suggests that quantum effects play a decisive role in .
4 More- Received 4 April 2016
- Revised 26 October 2017
DOI:https://doi.org/10.1103/PhysRevB.96.235117
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