| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for growing a good single crystal of a group Va element diboride [MB2 (M is V, Nb or Ta)] having no crack and including no sub-boundary and involved material. SOLUTION: This method for growing a single crystal of a group Va element diboride consisting of MB2 (M is V, Nb or Ta) by a floating zone method comprises decreasing a growing temperature by regulating a melt zone composition (the atomic ratio of B/M) so as to be 2.2-5, and regulating the growing rate so as to be within the range of 0.3-2 cm/hr to reduce the generation of crack in the crystal to be obtained. The growing is carried out by the constitution having an upper shaft 2, a lower shaft 2', holders 3, 3', a working coil 4, a raw material-sintered rod S, a melting zone 6, a single crystal 7, a sintered rod 8 and a boron sintered body 9 for controlling the initial composition of the melt zone. The heating of a sample is carried out by sending a high frequency current to a working coil 4 to generate an induced current in the sample, and to heat the sample by the Joule heat caused by the induced current. A raw material rod 6 is sent to the melt zone 6 formed in this way from the upper side, and the single crystal 7 is grown at the lower side.
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