Superconducting Properties and Possible Vortex Phase Diagram in a Thick Amorphous MgxB1-xFilm

We report on the superconducting properties in a thick amorphous MgxB1-x film, which was prepared by coevaporation of pure Mg and B. Measurements of the current-voltage characteristics and the AC complex resistivity in magnetic fields indicate the presence of the vortex-glass transition. Based on the data, we construct the possible phase diagram in the field-temperature plane. We find that there is the large vortex-liquid phase, which persists down to low temperatures.