Superconducting Transition in the $\beta$-Pyrochlore AOs${}_2$O${}_6$ (A=Cs, Rb, K) under Pressure

Abstract

Pressure dependence of superconducting transition temperature $T_{\mathrm{c}}$ has been determined through the DC magnetic measurements under pressure up to $P$=10 GPa for $\beta$-pyrochlore oxides AOs${}_2$O${}_6$ with A=Cs ($T_{\mathrm{c}}$=3.3 K), Rb (6.3 K) and K (9.6 K). Both for A=Rb and Cs, $T_{\mathrm{c}}$ increases with increasing $P$ and shows a saturation at $T_{\mathrm{cm}}$$\sim$8.8 K, which is considered as the upper limit of $T_{\mathrm{c}}$ inherent in AOs${}_2$O${}_6$. In contrast, the $T_{\mathrm{c}}-P$ curve for KOs${}_2$O${}_6$ shows a sharp maximum of $\sim$10 K at $P$$\sim$0.5 GPa, and $T_{\mathrm{c}}$ is higher than $T_{\mathrm{cm}}$ for 0$\le$$P$$\le$1.5GPa, suggesting the enhanced superconductivity due to the rattling of K ions.

4 pages, 4 figures, to be published in J. Phys. Soc. Jpn. Vol. 77, No. 4 (2008)

References in corpus (4)

• Extremely strong-coupling superconductivity and anomalous lattice properties in the beta-pyrochlore oxide KOs2O6
• Chemical trends of superconducting properties in pyrochlore oxides
• Metal-insulator Transition in a Pyrochlore-type Ruthenium oxide, Hg2Ru2O7
• Vortex Redistribution below the First-Order Transition Temperature in the β-Pyrochlore Superconductor KOs_2O_6

Cited by in corpus (2)

• Rattling-Induced Superconductiviy in the Beta-Pyrochlore Oxides AOs2O6
• A Possible Phase Transition in beta-pyrochlore Compounds