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Anomalous magnetic phase in an undistorted pyrochlore oxide Cd2Os2O7 induced by geometrical frustration

A. Koda·R. Kadono·K. Ohishi·S. R. Saha·W. Higemoto·S. Yonezawa·Y. Muraoka·Z. Hiroi
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Abstract

We report on the muon spin rotation/relaxation study of a pyrochlore oxide, Cd2Os2O7, which exhibits a metal-insulator (MI) transition at T_{MI}~225 K without structural phase transition. It reveals strong spin fluctuation (>10^8/s) below the MI transition, suggesting a predominant role of geometrical spin frustration amongst Os^{5+} ions. Meanwhile, upon further cooling, a static spin density wave discontinuously develops below T_{SDW}~150 K. These observations strongly suggest the occurrence of an anomalous magnetic transition and associated change in the local spin dynamics in undistorted pyrochlore antiferromagnet.

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A. Koda, R. Kadono, K. Ohishi, S. R. Saha, W. Higemoto, S. Yonezawa, Y. Muraoka, Z. Hiroi. 2007-03-26. Anomalous magnetic phase in an undistorted pyrochlore oxide Cd2Os2O7 induced by geometrical frustration. https://doi.org/10.1143/jpsj.76.063703

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