Synthesis and processing of Al sheathed MgB 2 tapes by powder in tube method and determination of superconducting and mechanical properties

Abstract

The discovery of superconductivity at 39 K in magnesium diboride (MgB 2) has assumed significance theoretically and experimentally, on the grounds of the fact that it has the highest superconducting transition temperature in the conventional intermetallic superconductors reported so far. After the discovery of superconductivity in MgB 2, attempts have been made to synthesize this material in order to improve its superconducting properties. Different methods on the synthesis of MgB 2 tapes and wires have been developed by the scientists. Powder in tube (PIT) method seems to be more promising and practical than the others and this method is the most popular in producing good quality wires and tapes. In this study, MgB 2 was synthesized with conventional solid state reaction from magnesium and boron powders. The reactants were milled mechanically in attrition type device with a cooling jacket. The processed powders were sintered in a quartz tube under an argon atmosphere. MgB 2 was filled into Al tube and annealed at different times and temperatures. Superconducting and mechanical properties of MgB 2/Al tapes were determined.