Specific Heat of the beta-Pyrochlore Oxide Superconductors CsOs2O6 and RbOs2O6
Zenji Hiroi, Shigeki Yonezawa, Takaki Muramatsu, Jun-Ichi Yamaura, Yuji Muraoka
Abstract
Two beta-pyrochlore oxide superconductors, CsOs2O6 and RbOs2O6, are studied thermodynamically by measuring specific heat on polycrystalline samples. It is found that a Sommerfeld coefficient ? is nearly equal, 20 mJ/K2 mol Os, in the two oxides with different superconducting transition temperatures; Tc = 3.3 K and 6.3 K, respectively. This suggests that the density of states at the Fermi level is not a crucial parameter to determine the Tc of the beta-pyrochlore oxide superconductors, which is incompatible with the general expectation for a conventional BCS-type superconductor. Anomalous lattice contributions to specific heat at low temperature are also reported, which may come from nearly localized phonon modes associated with the rattling of the alkali metal ions weakly bound in an oversized cage formed by OsO6 octahedra.
Create a lesson
Related papers
Superconductivity in Pb2-xBixPd Single Crystals
S. Srivastava, R. P. Singh
Type-I superconductivity in a quasi-2D topologically nontrivial YbBi2
Karolina Górnicka, Sudip Malick, Joanna Bławat et al.
Generic thermodynamics of condensates with extremely small superfluid density ---Application to UTe2 and hidden second phase transition---
Kazushige Machida
Vortex-mediated spin current injection into two-dimensional superconductor NbSe2
Meng Yang, Xiaolong Yin, Jingjing Liu et al.
Superconductivity at the metal-insulator phase boundary in a bulk nickelate at ambient pressure
Hyo-Bin Ahn, Xinglong Chen, Hong Zheng et al.
Crystallographic imperfections and exotic superconductivity of UBe13
Andreas Leithe-Jasper, Markus König, Yusei Shimizu et al.