Some aspects of material preparation in magnesium diboride: Thin films growth and tapes fabrication

In this paper a short description of the problems related to the preparation of magnesium diboride samples in form of bulk, thin films and tapes is given. The principal problem is that Mg is highly volatile: this fact imposes severe constraints to the sample preparatation. We briefly review the activity in this field of the INFM-LAMIA laboratory. A method has been developed to prepare very clean and dense bulk samples with good transport properties in a single step, starting from pure elements. In the tapes fabrication, very promising results are obtained with a powder in tube procedure: the low cost and the good results obtained in term of critical current density make this compound interesting for the applications. The various thin film deposition techniques developed will be also shortly reviewed with particular regard to the in situ ones