arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0802.3273cond-mat.supr-concond-mat.mtrl-sci
收藏

超导体CaC6的压力诱导有序-无序相变

Pressure-induced order-disorder phase transition in superconducting CaC6

A. Gauzzi, N. Bendiab, M. d'Astuto, B. Canny, M. Calandra, F. Mauri, G. Loupias, N. Emery, C. Herold, P. Lagrange, M. Hanfland, M. Mezouar

摘要:

本文用同步辐射X射线衍射方法研究了高达13 GPa的高压对超导CaC_6室温晶体结构的影响。在此P范围内,未发现原始空间群对称性\textit{R\=3m}的变化,但在9 GPa,即接近最近报道的临界T_c降低值时,我们观察到了伴随着Bragg峰大幅度加宽的压缩性跳跃。降压和对称性参数的可逆性后的两种效果给出了证据的有序-无序相变的第二顺序,推测与Ca亚晶格,这提供了一个完整的帐户上述Tc减少。

英文摘要:

By means of synchrotron X-ray diffraction, we studied the effect of high pressure, P, up to 13 GPa on the room temperature crystal structure of superconducting CaC6. In this P range, no change of the pristine space group symmetry, \textit{R\=3m}, is found. However, at 9 GPa, i.e. close to the critical value at which a large T_c reduction was reported recently, we observed a compressibility jump concomitant to a large broadening of Bragg peaks. The reversibility of both effects upon depressurization and symmetry arguments give evidence of an order-disorder phase transition of second order, presumably associated with the Ca sublattice, which provides a full account for the above Tc reduction.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑