2002 年 49 巻 7 号 p. 588-592
It is revealed recently that the familiar chemical compound MgB2 is a superconducting material and the superconducting transition temperature Tc is 39 K 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 C 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, so that the superconducting properties are assumed to be improved and the production process of MgB2 becomes simple.