earticle

영어

Single-crystal like MgB2 thin film was grown on (000l) Al2O3 substrate by using hybrid physical-chemical vapor deposition (HPCVD) system. Single crystal properties were studied by X-ray diffraction (XRD) and the full width at half maximum (FWHM) of the (0001) MgB2 peak is 0.15°, which is very close to that has been reported for MgB2 single- crystal. It indicates that the crystalline quality of thin film is good. Temperature dependence on resistivity was investigated by physical property measurement system (PPMS) in various applied fields from 0 to 9 T. The upper critical field (Hc2) and irreversibility field (Hirr) were determined from PPMS data, and the estimated values are comparable with that of MgB2 single- crystals. The thin film shows a high critical temperature (Tc) of 40.4 K with a sharp superconducting transition width of 0.2 K, and a high residual resistivity ratio (RRR=21), it reflects that MgB2 thin film has a pure phase structure.