Anomalous Magnetic Phase in an Undistorted Pyrochlore Oxide Cd2Os2O7 Induced by Geometrical Frustration

Akihiro Koda; Ryosuke Kadono; Kazuki Ohishi; Shanta R. Saha; Wataru Higemoto; Shigeki Yonezawa; Yuji Muraoka; Zenji Hiroi

doi:10.1143/jpsj.76.063703

Anomalous Magnetic Phase in an Undistorted Pyrochlore Oxide Cd₂Os₂O₇ Induced by Geometrical Frustration

Akihiro Koda, Ryosuke Kadono, Kazuki Ohishi, Shanta R. Saha, Wataru Higemoto, Shigeki Yonezawa, Yuji Muraoka, Zenji Hiroi

Author information

Akihiro Koda
Muon Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK)
Department of Materials Structure Science, The Graduate University for Advanced Studies (SOKENDAI)
Ryosuke Kadono
Muon Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK)
Department of Materials Structure Science, The Graduate University for Advanced Studies (SOKENDAI)
Kazuki Ohishi
Muon Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK)
Shanta R. Saha
Muon Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK)
Wataru Higemoto
Advanced Science Research Center, Japan Atomic Energy Agency
Shigeki Yonezawa
Institute for Solid State Physics, University of Tokyo
Yuji Muraoka
Institute for Solid State Physics, University of Tokyo
Zenji Hiroi
Institute for Solid State Physics, University of Tokyo

Keywords: μSR, strongly correlated electron, metal–insulator transition, SDW, frustrated magnetism

JOURNAL RESTRICTED ACCESS

2007 Volume 76 Issue 6 Pages 063703

DOI https://doi.org/10.1143/jpsj.76.063703

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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\\simeq225 K without structural phase transition. It reveals strong spin fluctuation (≥10⁸ s⁻¹) below the MI transition, suggesting a predominant role of geometrical spin frustration amongst Os⁵⁺ ions. Meanwhile, upon further cooling, an incommensurate spin density wave discontinuously develops below T_SDW\\simeq150 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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