| Autor: |
Shyam Sundar, L S Sharath Chandra, M K Chattopadhyay, Sudhir K Pandey, D Venkateshwarlu, R Rawat, V Ganesan, S B Roy |
| Jazyk: |
angličtina |
| Rok vydání: |
2015 |
| Předmět: |
|
| Zdroj: |
New Journal of Physics, Vol 17, Iss 5, p 053003 (2015) |
| Druh dokumentu: |
article |
| ISSN: |
1367-2630 |
| DOI: |
10.1088/1367-2630/17/5/053003 |
| Popis: |
Superconducting transition temperature T _C of some of the cubic β phase ${\rm M}{{{\rm o}}_{1-x}}$ Re _x alloys with $x\gt 0.10$ is an order of magnitude higher than that in the elements Mo and Re. We investigate this rather enigmatic issue of the enhanced superconductivity with the help of experimental studies of the temperature dependent electrical resistivity ( ρ ( T )) and heat capacity ( C _P ( T )), as well as the theoretical estimation of electronic density of states (DOS) using band structure calculations. The ρ ( T ) in the normal state of the ${\rm M}{{{\rm o}}_{1-x}}$ Re _x alloys with $x\geqslant 0.15$ is distinctly different from that of Mo and the alloys with $x\lt 0.10.$ We have also observed that the Sommerfeld coefficient of electronic heat capacity γ , superconducting transition temperature T _C and the DOS at the Fermi level show an abrupt change above $x\gt 0.10$ . The analysis of these results indicates that the value of electron–phonon coupling constant λ _ep required to explain the T _C of the alloys with $x\gt 0.10$ is much higher than that estimated from γ . On the other hand the analysis of the results of the ρ ( T ) reveals the presence of phonon assisted inter-band s–d scattering in this composition range. We argue that a strong electron–phonon coupling arising due to the multiband effects is responsible for the enhanced T _C in the β phase ${\rm M}{{{\rm o}}_{1-x}}$ Re _x alloys with $x\gt 0.10$ . |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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