Microscopic spin Hamiltonian for a dipolar-Heisenberg magnet LiGdF4 from EPR measurements

Abstract

Low-temperature electron paramagnetic resonance measurements are performed on single crystals of LiY_{1-x}Gd_xF_4 with weak x=0.005 and moderate x=0.05 concentration of Gd ions. Modeling of the experimental spectra allows us to precisely determine microscopic parameters of the spin Hamiltonian of the parent LiGdF4 material, including the nearest-neighbor exchange constant. The obtained parameters are further tested by comparing a strongly anisotropic Curie-Weiss temperature obtained for LiGdF4 in our static magnetization measurements with theoretically computed values. We find a fine balance between principal magnetic interactions in LiGdF4, which results in a hidden magnetic frustration presumably leading to a delayed magnetic ordering and an enhanced magnetocaloric effect at low temperatures.

arXiv comment6 pages, 6 figures

References in corpus (6)

• Magnetic Pyrochlore Oxides
• Quantum Phase Transition of a Magnet in a Spin Bath
• Magnetocaloric effect in pyrochlore antiferromagnet Gd2Ti2O7
• Neutron spectroscopic study of crystal-field excitations and the effect of the crystal field on dipolar magnetism in Li$R$F${}_4$ ($R$ = Gd, Ho, Er, Tm, and Yb)
• Probing strongly hybrid nuclear-electronic states in a model quantum ferromagnet
• Spin dynamics of the quantum dipolar magnet Yb${}_3$Ga${}_5$O${}_{12}$ in an external field

Cited by in corpus (1)

• Chiral magnetic phases in Moire bilayers of magnetic dipoles