Spin freezing in the disordered pyrochlore magnet NaCaCo2F7: NMR studies and Monte Carlo simulations

R. Sarkar, J. W. Krizan, F. Brückner, E. C. Andrade, S. Rachel, M. Vojta, R. J. Cava, and H.-H. Klauss
Phys. Rev. B 96, 235117 – Published 12 December 2017

Abstract

We present results of Na23 and F19 nuclear magnetic resonance (NMR) measurements on NaCaCo2F7, a frustrated pyrochlore magnet with a Curie-Weiss temperature ΘCW140 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.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
4 More
  • Received 4 April 2016
  • Revised 26 October 2017

DOI:https://doi.org/10.1103/PhysRevB.96.235117

©2017 American Physical Society

Physics Subject Headings (PhySH)

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

R. Sarkar1,*, J. W. Krizan2, F. Brückner1, E. C. Andrade3,4, S. Rachel5,6, M. Vojta5, R. J. Cava2, and H.-H. Klauss1

  • 1Institut für Festkörperphysik, Technische Universität Dresden, 01062 Dresden, Germany
  • 2Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA
  • 3Instituto de Física Teórica, Universidade Estadual Paulista, Rua Dr. Bento Teobaldo Ferraz, 271 - Bloco II, 01140-070 São Paulo, São Paulo, Brazil
  • 4Instituto de Física de São Carlos, Universidade de São Paulo, Caixa Postale 369, São Carlos, São Paulo 13560-970, Brazil
  • 5Institut für Theoretische Physik, Technische Universität Dresden, 01062 Dresden, Germany
  • 6School of Physics, University of Melbourne, Parkville, Victoria 3010, Australia

  • *rajibsarkarsinp@gmail.com

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 96, Iss. 23 — 15 December 2017

Reuse & Permissions
Access Options
CHORUS

Article Available via CHORUS

Download Accepted Manuscript
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review B

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×