Lutskiy D. Elaboration technology of the growth method of Sb-Bi alloys gradient crystals

The thesis dedicated the elaborating of new growth method SbxBi1-x alloy gradient single crystals with a lattice parameter gradient up to 1%/cm along the bulk. Sb-Bi gradient single crystals with Bi composition from 2 to 18 at% have been grown by a modified Czochralski method with Bi feed. The growth conditions of SbxBi1-x alloy single crystals and density of dislocations in them was experimentally investigated. The dislocations density along of the bulk increased from 3,0•106 сm-2 to 1,73•107 cm-2 in these single crystals.This Sb-Bi alloy single crystal had the gradient of Bi concentration of 14.5 at%/cm and a lattice parameter gradient of 0.85%/cm. The electron concentration in the single crystals changed from 4.2•1018 to 6•1018cm-3 and the carrier mobilities from 1.22•104 to 1.12•104 cm2/V s, respectively. The measured thermo emf in these crystals decreased from 81 to 21 mV/K with the increase of Bi composition up to 18 at%.