Lattice Mismatch Driven In Plane Strain Engineering for Enhanced Upper Critical Fields in Mo2N Superconducting Thin Films

TL;DR

This study investigates how substrate-induced strain affects the superconducting properties of Mo2N thin films, demonstrating that strategic substrate choice can enhance critical fields and electron-phonon coupling.

Contribution

It provides new insights into strain engineering in Mo2N superconducting films, showing substrate selection as a method to tune superconducting properties.

Findings

Superconducting transition temperatures of 5.2 K and 5.6 K.

Upper critical fields of 5 T and 7 T.

Strain from substrates influences electron-phonon coupling.

Abstract

Transition metal nitrides are a fascinating class of hard coating material that provide an excellent platform for investigating superconductivity and fundamental electron phonon interactions. In this work the structural morphological and superconducting properties have been studied for Mo2N thin films deposited via direct current magnetron sputtering on cplane Al2O3 and MgO substrates to elucidate the effect of internal strain on superconducting properties. High resolution X Ray diffraction and time of flight elastic recoil detection analysis confirms the growth of single phase Mo2N thin films exhibiting epitaxial growth with twin domain structure. Low temperature electrical transport measurements reveal superconducting transitions at 5.2 K and 5.6 K with corresponding upper critical fields of 5 T and 7 T for the films deposited on Al2O3 and MgO, respectively. These results indicate strong type II superconductivity and the observed differences in superconducting properties are attributed to substrate induced strain which leads to higher e ph coupling for the film on MgO substrate. These findings highlight the tunability of superconducting properties in Mo2N films through strategic substrate selection.