Properties of MgB ₂ thin films with carbon doping

The structural and superconducting properties of MgB ₂ thin films doped with carbon during the hybrid physical-chemical vapor deposition process were analyzed. To achieve carbon doping, a carbon-containing precursor metalorganic bis(methylcyclopentadienyl)magnesium was added to the carrier gas. It was observed that as the amount of carbon in the film increases, the resistivity increases, T _c decreases and the upper critical field increases dramatically as compared to clean films. The results show that the carbon doping approach can be used top produce MgB ₂ materials for high magnetic-field applications.