Dipolar spin ice states with a fast monopole hopping rate in CdEr2X4 ( X=Se , S)

Gao, Shang, Zaharko, O., Tsurkan, V., Prodan, L., Riordan, E., Lago, J., Fåk, B., Wildes, A. R., Koza, M. M., Ritter, C., Fouquet, P., Keller, L., Canévet, E., Medarde, M., Blomgren, J., Johansson, C., Giblin, S. R. ORCID: https://orcid.org/0000-0003-1876-8619, Vrtnik, S., Luzar, J., Loidl, A., Rüegg, Ch. and Fennell, T. 2018. Dipolar spin ice states with a fast monopole hopping rate in CdEr2X4 ( X=Se , S). Physical Review Letters 120 (13) , 137201. 10.1103/PhysRevLett.120.137201

Preview

PDF - Published Version Download (410kB) | Preview

Abstract

Excitations in a spin ice behave as magnetic monopoles, and their population and mobility control the dynamics of a spin ice at low temperature. CdEr 2 Se 4 is reported to have the Pauling entropy characteristic of a spin ice, but its dynamics are three orders of magnitude faster than the canonical spin ice Dy 2 Ti 2 O 7 . In this Letter we use diffuse neutron scattering to show that both CdEr 2 Se 4 and CdEr 2 S 4 support a dipolar spin ice state—the host phase for a Coulomb gas of emergent magnetic monopoles. These Coulomb gases have similar parameters to those in Dy 2 Ti 2 O 7 , i.e., dilute and uncorrelated, and so cannot provide three orders faster dynamics through a larger monopole population alone. We investigate the monopole dynamics using ac susceptometry and neutron spin echo spectroscopy, and verify the crystal electric field Hamiltonian of the Er 3 + ions using inelastic neutron scattering. A quantitative calculation of the monopole hopping rate using our Coulomb gas and crystal electric field parameters shows that the fast dynamics in CdEr 2 X 4 ( X = Se , S) are primarily due to much faster monopole hopping. Our work suggests that CdEr 2 X 4 offer the possibility to study alternative spin ice ground states and dynamics, with equilibration possible at much lower temperatures than the rare earth pyrochlore examples.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Physics and Astronomy
Publisher:	American Physical Society
ISSN:	0031-9007
Date of First Compliant Deposit:	5 April 2018
Date of Acceptance:	30 March 2018
Last Modified:	05 May 2023 17:06
URI:	https://orca.cardiff.ac.uk/id/eprint/110511

Citation Data

Cited 13 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item