Highly c-axis oriented MgB2 thin films with TC,onset of 39.6K were fabricated by Mg diffusion into pulsed-laser-deposited B precursors. The estimation of critical current density JC, using hysteresis loops and the Bean model, had given the value of 107A/cm2 (15K, 0T), which was one of the highest values ever reported. The X-ray photo-emission study of the MgB2 thin films had revealed that the binding energies of Mg 2p and B 1s were at 49.4 and 186.9eV, which were close to those of metallic Mg and transition-metal diborides, respectively.

Superconductivity and X-ray Photoemission Study of MgB2 Thin Films. S.F.Wang, Y.L.Zhou, Y.B.Zhu, Q.Zhang, K.Xie, Z.H.Chen, H.B.Lu, G.Z.Yang: Chinese Physics, 2002, 11, 1300-2