Superconducting Properties of MgCNi3 Films

TL;DR

This study investigates the superconducting and magnetotransport properties of thin MgCNi3 films, revealing their critical temperatures, fields, and carrier densities, which are comparable or higher than bulk samples.

Contribution

It provides detailed characterization of MgCNi3 thin films, including transition temperatures, critical fields, and carrier densities, advancing understanding of their superconducting properties.

Findings

Films thicker than 40 nm have Tc ~ 8 K and Hc2 ~ 14 T.

Carrier density in films is approximately four times higher than in bulk samples.

Superconducting properties of films are comparable to those of polycrystalline powders.

Abstract

We report the magnetotransport properties of thin polycrystalline films of the recently discovered non-oxide perovskite superconductor MgCNi3. CNi3 precursor films were deposited onto sapphire substrates and subsequently exposed to Mg vapor at 700 C. We report transition temperatures (Tc) and critical field values (Hc2) of MgCNi3 films ranging in thickness from 7.5 nm to 100 nm. Films thicker than ~40 nm have a Tc ~ 8 K, and an upper critical field Hc2 ~ 14 T, which are both comparable to that of polycrystalline powders. Hall measurements in the normal state give a carrier density, n =-4.2 x 10^22 cm^-3, that is approximately 4 times that reported for bulk samples.