Rapid solidification processing and characterization of semiconducting In_x, Ga_1-x alloys

Abstract

Vacuum-sealed In_x, Ga_1-x, (x = 0·1 1–0·93) alloys were rapidly solidified at cooling rates greater than l0⁶ Ks^−l by ejecting melts on to a rotating copper disc. Thin flake or alloy powder formation was studied at disc spinning velocities in the approximate range 14–64ms⁻¹. X-ray diffraction, transmission electron microscopy and thermal analyses revealed non-equilibrium microcrystalline phases in the flakes and powders with average grain sizes varying from about 2·7 to 7 μAmorphous phase formation was also observed in powders of two indium concentrations (x = 0·51 and x = 0middot;44) at disc velocities of about 25 and 64ms^−l. Electrical resistivity data (100–400°c) on flakes of the x = 0·51 alloy suggest a resistivity minimum at about 100°C.