Roles of the strong spin-phonon coupling in the geometrically frustrated pyrochlore Y2Ru2O7

Abstract We investigated temperature-dependent infrared-active transverse phonon modes of insulating pyrochlore Y 2 Ru 2 O 7 , which shows a spin-glass-like transition around 80 K. We found quite abnormal temperature-dependent behaviors for some phonon modes, which should be contributed by a strong antiferromagnetic correlation, not by a structural distortion. Through quantitative analysis, we suggested that the strong spin–phonon coupling effects should play an important role in the intriguing magnetic state of this geometrically frustrated compound.