Superconductivity in layered lanthanum carbide halides:: La2C2(X,X′)2 (X,X′ =Cl, Br, I)

被引：5

作者：

Ahn, K ^{[1
]}

Kremer, RK ^{[1
]}

Mattausch, H ^{[1
]}

Simon, A ^{[1
]}

机构：

[1] Max Planck Inst Festkorperforsch, D-70569 Stuttgart, Germany

来源：

JOURNAL OF ALLOYS AND COMPOUNDS | 2000年 / 303卷

关键词：

superconductivity; rare-earth metal carbide halides; neutron diffraction; susceptibility;

D O I：

10.1016/S0925-8388(00)00669-1

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 [物理化学]; 081704 [应用化学];

摘要：

The superconducting properties of the layered lanthanum carbide halides La2C2X2 (X=Br, I) and mixed halides are investigated. These compounds show superconductivity at 7.03(5) for X=Br and at approximate to 1.7 K for X=I, respectively. Selected compositions were investigated using high-resolution neutron powder diffraction measurements from room temperature to 1.5 K. Rietveld refinements of the powder patterns yield the structural parameters, in particular of the C atoms. These allow us to follow in detail the variation of the interatomic distances in the C-2 group. The low-temperature structural parameters are taken as inputs to perform Extended Huckel band structure calculations which allow us to identify a band of low dispersion along the Gamma-N direction in the Brillouin zone. We discuss correlations of structural and electronic properties of the La2C2(X,X')(2) phase with the superconducting transition temperatures. (C) 2000 Elsevier Science S.A. All rights reserved.

引用

页码：257 / 261

页数：5

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