Structure of the Eutectic in the LaB₆–ScB₂ System

Abstract

LaB₆–ScB₂ system alloys have been synthesized using electron-beam melting and am induction installation for crucibleless melting in pure helium. The metallographic and x-ray analyses methods have been used to establish that the alloys yield eutectic with 50 wt.%, 56 vol.%, and 78 mol.% of ScB₂, whose colonies solidify in the form of cubic bicrystalline lanthanum hexaboride and undulated plates of scandium diboride, which divide into rods under the influence of scandium dodecaboride ScB₁₂, resulting from scandium evaporation.