Salvador Villarreal1,Isaías Rodríguez1,David Hinojosa-Romero1,Renela Valladares2,Alexander Valladares2,Ariel Valladares1
Instituto de Investigaciones en Materiales, UNAM1,Facultad de Ciencias, UNAM2
Salvador Villarreal1,Isaías Rodríguez1,David Hinojosa-Romero1,Renela Valladares2,Alexander Valladares2,Ariel Valladares1
Instituto de Investigaciones en Materiales, UNAM1,Facultad de Ciencias, UNAM2
Pure copper is a metal with a high conductivity which is normally attributed to its low electron-phonon coupling strength. This characteristic result indicates that if copper undergoes a superconducting transition at all, then it must be at a very low temperature, according to the conventional theories of superconductivity. This premise is confirmed by the fact that pure copper does not superconduct at temperatures so far studied. However, many materials that include copper in their composition have been found to be superconducting, including transition metal alloys. In particular, amorphous alloys in the Cu<sub>x</sub>Zr<sub>1-x</sub> system have been found to be superconducting while their crystalline counterparts have not [1, 2]. Here we combine the McMillan approach [3] and our computational results for the amorphous alloys to revisit superconductivity in the Cu<sub>x</sub>Zr<sub>1-x</sub> system at various concentrations and to calculate some of its fundamental superconducting properties. <i>Ab initio</i> DFT molecular dynamics was used, together with the <i>undermelt-quench</i> approach developed within our group [4], to generate amorphous supercells with 216 atoms. Electronic and vibrational properties were obtained for these structures and used to estimate the transition temperatures of some of the specimens studied through the McMillan approach. An analysis of the results obtained will be presented and conclusions put forth.<br/>References<br/>[1] Arias, D., & Abriata, J. P. (1990). Cu-Zr (copper-zirconium). <i>Journal of Phase Equilibria</i>, <i>11</i>(5), 452–459. https://doi.org/10.1007/bf02898260<br/>[2] Garoche, P., & Veyssie, J. J. (1981). Superconductivity in amorphous versus Crystalline Cu<sub>0.33</sub>Zr<sub>0.66</sub> alloys. <i>Journal De Physique Lettres</i>, <i>42</i>(15), 365–368. https://doi.org/10.1051/jphyslet:019810042015036500<br/>[3] McMillan, W. L. (1968). Transition temperature of strong-coupled superconductors. <i>Physical Review</i>, <i>167</i>(2), 331–344. https://doi.org/10.1103/physrev.167.331<br/>[4] Valladares, A. A. (2008). In J. C. Wolf & L. Lange (Eds.), <i>Glass Materials Research Progress</i> (pp. 61–123). Nova Science Publishers, Inc.