Two-mode behavior for the E2g broad band in Mg(B1-xCx)2

被引：4

作者：

Parisiades, P. ^{[1
]}

Lampakis, D. ^{[1
]}

Palles, D. ^{[1
]}

Liarokapis, E. ^{[1
]}

Zhigadlo, N. D. ^{[2
]}

Katrych, S. ^{[2
]}

Karpinski, J. ^{[2
]}

机构：

[1] Natl Tech Univ Athens, Dept Phys, GR-15780 Athens, Greece

[2] TH Zurich, Solid State Phys Lab, CH-8093 Zurich, Switzerland

来源：

PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS | 2008年 / 468卷 / 14期

基金：

瑞士国家科学基金会;

关键词：

superconductivity; MgB2; Raman spectroscopy;

D O I：

10.1016/j.physc.2008.05.219

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

A systematic Raman study has been carried out on single crystals of Mg(B1-x,C-x)(2) with carbon concentrations in the range of x = 0.0-0.15. We have found remarkable differentiations of the Raman spectra with doping. Even with small amounts of carbon substitution (x = 0.027) the E-2g-symmetry broad band at similar to 600cm(-1) (for pure MgB2) diminishes and new modes appear of the approximate A(1g)/B-1g (similar to 750 cm(-1)) and E-2g (similar to 850 cm(-1)) symmetries, though the transition temperature is only slightly reduced (< 2 K). The broadband does not evolve continuously into the mode of same symmetry at similar to 850 cm(-1), as assumed by other investigators, The practical disappearance of the original similar to 600 cm(-1) mode at x similar or equal to 0.08 coincides with the fast reduction of T-c. The doping dependence of the phonons indicates a two-mode behavior, which could be driven by the 2D-3D electronic topological transition and associated with a possible nanoscale phase separation. (c) 2008 Elsevier B.V. All rights reserved.

引用

页码：1064 / 1069

页数：6

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