Thermodynamic properties of binary Si–Y (transition metal) alloys

Abstract

The partial (for yttrium) mixing enthalpies (∆ m $$ {\overline H_Y} $$ ) of Si–Y molten alloys are determined using high-temperature isoperibolic calorimetry at 1770 ± 5 K for 0 < x y < 0.2. The integral mixing enthalpies (∆ m H) of Si–Y melts are calculated from these data. The formation of these molten alloys is accompanied by large exothermic heat effects. The generalized values of ∆ m H for molten Si–Y alloys are based on our and literary data. The activities of the melt components are calculated from liquidus coordinates of the Si–Y phase diagram. The values are characterized by very large negative deviations from the Raoult law. Correlation is established between the extremum of the integral mixing enthalpy for melts of silicon with d-metals and electronegativity differences and atomic radii of the alloy components.