Superconducting properties of MgCNi3 films -: art. no. 020501

We report the magnetotransport properties of thin polycrystalline films of the recently discovered nonoxide perovskite superconductor MgCNi3. CNi3 precursor films were deposited onto sapphire substrates and subsequently exposed to Mg vapor at 700degreesC. We report transition temperatures (T-c) and critical field values (H-c2) of MgCNi3 films ranging in thickness from 7.5 nm to 100 nm. Films thicker than approximate to40 nm have a T(c)similar to8 K, and an upper critical field H-c2(T=0)=14 T, which are both comparable to that of polycrystalline powders. Hall measurements in the normal state give a carrier density, n=-4.2x10(22) cm(-3), that is approximately 4 times that reported for bulk samples.