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arXiv · 0808.2331

Magnetic and charge transport properties of the Na-based Os oxide pyrochlore

Y. G. Shi·A. A. Belik·M. Tachibana·M. Tanaka·Y. Katsuya·K. Kobayashi·K. Yamaura·E. Takayama-Muromachi
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Abstract

Na-based osmium oxide pyrochlore was synthesized for the first time by an ion-exchange method. KOs2O6 was used as a host compound. Elelectron probe micro-analysis, synchrotron x-ray diffraction analysis, and thermo-gravimetric analysis confirmed its structure not as the beta-type but as the defect-type pyrochlore. The composition was identified as Na1.4Os2O6.H2O. Electrical resistivity, heat capacity, and magnetization measurements of the polycrystalline Na1.4Os2O6.H2O clarified absence of superconductivity above 2 K, being in contrast to what were found for the beta-pyrochlore AOs2O6 (A = Cs, Rb, K). Sommerfeld coefficient of 22 mJ K-2 mol-1 of Na1.4Os2O6.H2O was smallest among those of AOs2O6. A magnetic anomaly at ~57 K and possible associated magnetoresistance (+3.7 % at 2 K in 70 kOe) were found.

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Y. G. Shi, A. A. Belik, M. Tachibana, M. Tanaka, Y. Katsuya, K. Kobayashi, K. Yamaura, E. Takayama-Muromachi. 2008-08-18. Magnetic and charge transport properties of the Na-based Os oxide pyrochlore. https://doi.org/10.1016/j.jssc.2009.01.008

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