Phase separation in carbon-doped MgB2 superconductors

被引：31

作者：

Maurin, I ^{[1
]}

Margadonna, S

Prassides, K

Takenobu, T

Ito, T

Chi, DH

Iwasa, Y

Fitch, A

机构：

[1] Univ Sussex, Fullerene Sci Ctr, Sch Chem Phys & Environm Sci, Brighton BN1 9QJ, E Sussex, England

[2] Univ Cambridge, Dept Chem, Cambridge CB2 1EW, England

[3] NCSR Demokritos, Inst Mat Sci, Athens 15310, Greece

[4] Japan Adv Inst Sci & Technol, Tatsunokuchi, Ishikawa 9231292, Japan

[5] European Synchrotron Radiat Facil, F-38042 Grenoble, France

来源：

PHYSICA B-CONDENSED MATTER | 2002年 / 318卷 / 04期

基金：

日本学术振兴会;

关键词：

MgB2; superconductor; carbon doping; X-ray diffraction; phase separation;

D O I：

10.1016/S0921-4526(02)00811-6

中图分类号：

O469 [凝聚态物理学];

学科分类号：

070205 ;

摘要：

High-resolution synchrotron X-ray powder diffraction measurements have been carried out on superconducting MgB2-xCx (0less than or equal toxless than or equal to0.1) phases. The carbon miscibility in the hexagonal AlB2-type structure is very small, x<0.04. At higher carbon contents, macroscopic phase separation occurs leading to the coexistence of at least two phases, isostructural with the parent MgB2 compound. The coexisting phases differ mainly in their in-plane lattice constants, suggesting that boron is substituted by carbon in the boron layers, but in different concentrations. The multiphase samples still show a clear one-step superconducting transition and full shielding. chi = -1/4pi. (C) 2002 Elsevier Science B.V. All rights reserved.

引用

页码：392 / 397

页数：6

共 29 条

[1] The crystal structure of magnesium carbide [J].