Skip to main content

Magnetic interactions and spin dynamics in the bond-disordered pyrochlore fluoride NaCaCo2 F7

Author(s): Zeisner, Julian; Bräuninger, S. A.; Opherden, Lars; Sarkar, Denis Ivanovich; Gorbunov, Denis Ivanovich; et al

To refer to this page use:
Abstract: © 2019 American Physical Society. We report high-frequency/high-field electron spin resonance (ESR) and high-field magnetization studies on single crystals of the bond-disordered pyrochlore NaCaCo2F7. Frequency- and temperature-dependent ESR investigations above the freezing temperature Tf∼2.4 K reveal the coexistence of two distinct magnetic phases. A cooperative paramagnetic phase, evidenced by a gapless excitation mode, is found along with a spin-glass phase developing below 20 K which is associated with a gapped low-energy excitation. Effective g factors close to 2 are obtained for both modes, in line with pulsed high-field magnetization measurements which show an unsaturated isotropic behavior up to 58 T at 2 K. In order to describe the field-dependent magnetization in high magnetic fields, we propose an empirical model accounting for highly anisotropic ionic g tensors expected for this material and taking into account the strongly competing interactions between the spins which lead to a frustrated ground state. As a detailed quantitative relation between effective g factors as determined from ESR and the local g tensors obtained by neutron scattering [Ross, Phys. Rev. B 93, 014433 (2016)2469-995010.1103/PhysRevB.93.014433] is still sought after, our work motivates further theoretical investigations of the low-energy excitations in bond-disordered pyrochlores.
Publication Date: Apr-2019
Electronic Publication Date: 20-Apr-2019
Citation: Zeisner, J., Bräuninger, S.A., Opherden, L., Sarkar, R., Gorbunov, D.I., Krizan, J.W., Herrmannsdörfer, T., Cava, R.J., Wosnitza, J., Büchner, B., Klauss, H.H., Kataev, V. (2019). Magnetic interactions and spin dynamics in the bond-disordered pyrochlore fluoride NaCaCo2 F7. Physical Review B, 99 (15), 10.1103/PhysRevB.99.155104
DOI: doi:10.1103/PhysRevB.99.155104
ISSN: 2469-9950
EISSN: 2469-9969
Pages: 99.15:155104-1 -155104-8
Type of Material: Journal Article
Journal/Proceeding Title: Physical Review B
Version: Final published version. Article is made available in OAR by the publisher's permission or policy.
Notes: Physical Review B. Volume 99, Issue 15, 1 April 2019, Article number 155104.

Items in OAR@Princeton are protected by copyright, with all rights reserved, unless otherwise indicated.