In-situ growth of superconducting MgB2 thin films by molecular beam   epitaxy
  The in-situ growth of superconducting MgB2 thin films was examined from various perspectives. The paper discusses (1) growth temperature, (2) the effect of excess Mg, (3) the effect of residual gas during growth, (4) the effect of in-situ annealing, (5) thickness dependence and (6) the effect of substrates. Our results provide a guide to the preparation of high-quality superconducting MgB2 films for potential electronics applications. 
K Ueda, M. Naito