Correlation between Tc and Lattice Parameters of Novel Superconducting NaxCoO2 yH2O

H. Sakurai; K. Takada; T. Sasaki; F. Izumi; R. A. Dilanian; E. Takayama-Muromachi

doi:10.1143/JPSJ.73.2590

paper

Correlation between Tc and Lattice Parameters of Novel Superconducting NaxCoO2 yH2O

arXiv:cond-mat/0408428 · doi:10.1143/JPSJ.73.2590

Abstract

We synthesized the five batches of the samples of the novel P3 type superconductor, Na $_{x}$ (H $_{3}$ O) $_{y^{'}}$ CoO $_{2} \cdot y^{''}$ H $_{2}$ O, by the soft chemical process starting from $α$ -NaCoO $_{2}$ . The chemical and structural properties varied rather widely from batch to batch, with a result that $T_{c}$ varied from 4.6 K to 3.2 K. The magnetic susceptibility above $T_{c}$ shows upturn at low temperature as in the case of the P2 phase. The $T_{c}$ seems to be well correlated to the lattice parameters.

2 pages, 2 figures, and 1 table, to be published in J. Phys. Soc. Jpn. 73 (9) with possible minor revisions