Crystal Growth and Structure Analysis of a New Scandium Aluminum Boride Sc2AlB6

Abstract

Single crystals of a new ternary boride Sc2AlB6 were obtained from the Sc–Al–B system using high-temperature Al melts under an argon atmosphere. The growth conditions for large crystals were established. Sc2AlB6 crystals were obtained in the form of needle-like rectangles extending along the direction of the b axis or in the form of thick platelets with large c planes. The crystals were examined by powder X-ray diffraction and chemical analyses, and the crystal structure of Sc2AlB6 was investigated by single-crystal X-ray diffractometry. The crystal structure of Sc2AlB6 is of the Y2ReB6 type with the space group Pbam and the unit cell parameters are a=0.8937(3) nm, b=1.1226(3) nm, c=0.3433(1) nm, V=344.4(1)×10−3 nm3, Z=4. The structure refinement converged at an R(F2) value of 0.046 for 1545 reflections. The structural characteristics of Sc2AlB6 are discussed.