Point-contact measurements on the carbon and aluminium substituted MgB₂ samples are performed to study a development of the two gap superconductivity [1]. In the carbon substituted MgB₂ the large gap on the σ-band is decreased in an essentially linear fashion with increasing the carbon concentrations. The changes in the small gap Δ _π up to 3.8 % C are proportionally smaller but for the heavily doped sample with 10 % C and T_c = 22 K both gaps are still present, and significantly reduced, consistent with a strong essentially linear, reduction of each gap with the transition temperature [2,3]. A comparison with the aluminium doped material is made as well.


[1] P. Szabo et al., Phys. Rev. Lett. 87, 137005 (2001).
[2] P. Samuely et al., Phys. Rev. B 68, 020505(R) (2003).
[3] Z. Holanova et al., Phys. Rev. B accepted


* The work has been done in collaboration with P. Szabo, Z. Holanova, R.H.T. Wilke, S. Bud'ko and P.C. Canfield

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/2378 must be provided.