Spin-liquid dynamics of pyrochlore magnets Gd2Ti2O7 and Gd2Sn2O7

Abstract

The spin-liquid phase of two highly frustrated pyrochlore magnets Gd2Ti2O7 and Gd2Sn2O7 is probed using electron spin resonance in the temperature range 1.3 - 30 K. The deviation of the absorption line from the paramagnetic position ν=γH observed in both compounds below the Curie-Weiss temperature Θ_CW ~ 10 K, suggests an opening up of a gap in the excitation spectra. On cooling to 1.3 K (which is above the ordering transition T_N ~ 1.0 K) the resonance spectrum is transformed into a wide band of excitations with the gap amounting to Δ~ 26 GHz (1.2 K) in Gd2Ti2O7 and 18 GHz (0.8 K) in Gd2Sn2O7. The gaps increase linearly with the external magnetic field. For Gd2Ti2O7 this branch co-exists with an additional nearly paramagnetic line absent in Gd2Sn2O7. These low lying excitations with gaps, which are preformed in the spin-liquid state, may be interpreted as collective spin modes split by the single-ion anisotropy.

9 pages, 9 figures

References in corpus (10)

• Enhanced magnetocaloric effect in frustrated magnets
• Magnetic ordering in Gd2Sn2O7: the archetypal Heisenberg pyrochlore antiferromagnet
• Magnetocaloric effect in pyrochlore antiferromagnet Gd2Ti2O7
• Magnetic density of states at low energy in geometrically frustrated systems
• Quantum spin fluctuations in the dipolar Heisenberg-like rare earth pyrochlores
• Magnetic phase diagram of the antiferromagnetic pyrochlore Gd2Ti2O7
• Single-ion anisotropy in the gadolinium pyrochlores studied by an electron paramagnetic resonance
• ESR study of the single-ion anisotropy in the pyrochlore antiferromagnet Gd2Sn2O7
• Degeneracy and Strong Fluctuation-Induced First-Order Phase Transition in the Dipolar Pyrochlore Antiferromagnet
• Magnetic resonance in a pyrochlore antiferromagnet Gd2Ti2O7

Cited by in corpus (6)

• Magnetic Pyrochlore Oxides
• Signatures of low-energy fractionalized excitations in $\alpha$-RuCl${}_3$ from field-dependent microwave absorption
• Magnetic excitations in the XY-pyrochlore antiferromagnet Er${}_2$Ti${}_2$O${}_7$
• Long range order in the dipolar XY antiferromagnet Er${}_2$Sn${}_2$O${}_7$
• Magnetic excitations in dipolar pyrochlore antiferromagnet Gd${}_2$Sn${}_2$O${}_7$
• Magnetic interactions in the tripod-kagome antiferromagnet Mg${}_2$Gd${}_3$Sb${}_3$O${}_{14}$ probed by static magnetometry and high-field ESR spectroscopy