Transition metal nitrides are a fascinating class of hard coating material that provides an excellent platform for investigating superconductivity and fundamental electron-phonon (e-ph) interactions. In this work, the structural, morphological, and superconducting properties have been studied for Mo2N thin films deposited via direct current magnetron sputtering on c-plane 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 confirm the growth of single-phase Mo2N thin films exhibiting epitaxial growth with twin-domain structure. Low-temperature electrical transport measurements reveal superconducting transitions at approximate to 5.2 and approximate to 5.6 K with corresponding upper critical fields of approximate to 5 and approximate to 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.
Funding Agencies|Knut och Alice Wallenbergs Stiftelse