Floating zone growth and high-temperature hardness of YB_4 and YB_6 single crystals

摘要

High-quality YB_4 single crystals were prepared by controlling the composition of the atomic ratio, B/Y, of the molten zone to be 7-8. The preferential growth direction was almost normal to the (112) plane of the tetragonal crystal lattice, which had the lowest Vickers hardness. YB_6 crystals epitaxially grew on the YB_4 crystals. The growth rates of YB_4 and YB_6 crystals were inversely proportional to the difference in the composition between the crystal and the molten zone.