1. Magnetic and charge transport properties of the Na-based Os oxide pyrochlore
- Author
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Shi, Y.G., Belik, A.A., Tachibana, M., Tanaka, M., Katsuya, Y., Kobayashi, K., Yamaura, K., and Takayama-Muromachi, E.
- Subjects
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OSMIUM tetroxide , *MAGNETIC properties , *CHARGE transfer , *ELECTRON probe microanalysis , *THERMOGRAVIMETRY , *STRUCTURAL analysis (Science) , *X-ray diffraction - Abstract
Abstract: The Na-based osmium oxide pyrochlore was synthesized for the first time by an ion-exchange method using KOs2O6 as a host. The composition was identified as Na1.4Os2O6·H2O by electron probe micro-analysis, thermogravimetric analysis, and structural analysis using synchrotron X-ray diffraction. Na1.4Os2O6·H2O crystallizes in a regular pyrochlore structure with some defects (space group: Fd-3m, a=10.16851(1)Å). Electrical resistivity, heat capacity, and magnetization measurements clearly showed absence of superconductivity down to 2K, being in large contrast to what was found for the β-type pyrochlore superconductor AOs2O6 (A=Cs, Rb, and K). The Sommerfeld coefficient is 22mJK−2 mol−1, being the smallest among AOs2O6. A magnetic anomaly at ∼57K and associated magneto-resistance (+3.7% at 2K in 70kOe) were found. [Copyright &y& Elsevier]
- Published
- 2009
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