Spin freezing in the disordered pyrochlore magnet NaCaCo2 F7: NMR studies and Monte Carlo simulations
Publikation: Beitrag in Fachzeitschrift › Forschungsartikel › Beigetragen › Begutachtung
Beitragende
Abstract
We present results of Na23 and F19 nuclear magnetic resonance (NMR) measurements on NaCaCo2F7, a frustrated pyrochlore magnet with a Curie-Weiss temperature ΘCW≈-140 K and intrinsic bond disorder. Below 3.6 K both the Na23 and F19 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 F19 spin-lattice relaxation rate 19(1/T1) 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 NaCaCo2F7.
Details
Originalsprache | Englisch |
---|---|
Aufsatznummer | 235117 |
Fachzeitschrift | Physical Review B |
Jahrgang | 96 |
Ausgabenummer | 23 |
Publikationsstatus | Veröffentlicht - 12 Dez. 2017 |
Peer-Review-Status | Ja |