TiとBの生成熱を利用したMgB₂超電導体の燃焼合成法による製造

抄録

It is revealed recently that the familiar chemical compound MgB₂ is a superconducting material and the superconducting transition temperature Tc is 39K.It is not easy to produce the good MgB2 by conventional production method. The simple method to produce the MgB₂ in a short time is developed by means of a combustion synthesis process with the heat of formation of elements. MgB₂ is not able to be produced by a direct combustion synthesis process of Mg and B. Some main reasons are that the heat of formation of MgB₂ is small, Mg tends to vaporize, and the Mg powder is very rough but B powder is very fine. On the other hand, MgB₂ is able to be produced by the combustion synthesis process of Mg and B using the combustion synthesis of Ti and B proposed in the present paper. The oxidation and the vaporization of Mg are suppressed because the production is done in a very short time in a high vacuum. Moreover, the ratio of Mg and B is stabilized. Therefore, the superconducting properties are assumed to be improved and the production process of MgB₂ becomes simple.