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arXiv · 1104.1213

Magnetic transition, long-range order, and moment fluctuations in the pyrochlore iridate Eu2Ir2O7

Songrui Zhao. J. M. Mackie·D. E. MacLaughlin·O. O. Bernal·J. J. Ishikawa·Y. Ohta·S. Nakatsuji
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Abstract

Muon spin rotation and relaxation experiments in the pyrochlore iridate Eu2Ir2O7 yield a well-defined muon spin precession frequency below the metal-insulator/antiferromagnetic transition temperature TM = 120 K, indicative of long-range commensurate magnetic order and thus ruling out quantum spin liquid and spin-glass-like ground states. The dynamic muon spin relaxation rate is temperature-independent between 2 K and ~TM and yields an anomalously long Ir^{4+} spin correlation time, suggesting a singular density of low-lying spin excitations. Similar behavior is found in other pyrochlores and geometrically frustrated systems, but also in the unfrustrated iridate BaIrO3. Eu2Ir2O7 may be only weakly frustrated; if so, the singularity might be associated with the small-gap insulating state rather than frustration.

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Songrui Zhao. J. M. Mackie, D. E. MacLaughlin, O. O. Bernal, J. J. Ishikawa, Y. Ohta, S. Nakatsuji. 2011-04-06. Magnetic transition, long-range order, and moment fluctuations in the pyrochlore iridate Eu2Ir2O7. https://arxiv.org/abs/1104.1213

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