Physico-Chemical nanomaterials science

Restoration of the electron-phonon interaction function in an alloy molybdenum – rhenium
D’yachenko A.I.1, Kalenyuk O.A.1, Dmitrenko V.Yu.2, Tarenkov V.Yu.2
1 G. V. Kurdyumov Institute for Metal Physics, NAS of Ukraine, 36 Academician Vernadsky Blvd., UA-03142 Kyiv, Ukraine.
2 Donetsk Institute for Physics and Engineering Named after O. O. Galkin, NAS of Ukraine, 46 Nauky Ave., UA-03028 Kyiv, Ukraine.
E-mail: dmitrenko_v@ukr.net

The superconducting transition temperature of the Mo-Re alloy reaches to TC = 12–14 K, which significantly exceeds the TC value for Mo (TC = 1K) and Re (TC = 1.5K) crystals [1]. The reason for such a strong increase of TC is still not well understood. One of the most reliable and accurate methods for studying the mechanisms of electron-phonon interaction (EPI), including the tunneling density of states N()=Re{/[2-2()]1/2} (() – complex parameter of the energy gap of a superconductor) and the function of the electron-phonon interaction α2(ω)F(ω), is tunneling spectroscopy. A key limitation of this method is the preparation of the tunnel junctions. In this work, the EPI mechanism for the сплава Mo0.73Re0.27 alloy is studied for the first time by processing the characteristics of Ag-I-MoRe tunnel contacts, in which a dielectric layer I is formed on the natural MoRe oxide. The parabolic type of conductivity dI/dV, as well as a well-defined feature associated with the energy gap of the Mo0.73Re0.27 superconducting state and the features of the phonon spectrum, made it possible to reconstruct the EPI function of the Mo0.73Re0.27 alloy using the program [2]. The reliable values of the parameters of the energy gap, , and the EPI constant, , in Mo0.73Re0.27 were obtained, which makes it possible to refine the parameter (TC) of the Mo1–xRex alloys.

1.	Tulina N.A. and Zaitsev S.V. Point-contact spectroscopy study of classical vibrations in molybdenum – rhenium alloys // Solid State Commun. – 1993. – 86, № 1. – P. 55-57. 
2.	D'yachenko A.I. Extraction of the Eliashberg function from tunneling data. The method and the program // doi.org/10.48550/arXiv.cond-mat/0309479.