A MATHEMATICAL ANALYSIS OF SOLUTE REDISTRIBUTION DURING SOLIDIFICATION

A mathematical analysis is made of the redistribution of solute which occurs during the solidification, without convection, of a single-phase alloy. Calculations of solute distributions are carried out for steady state conditions, and for the transient changes in solute concentration, both in the solid and in the liquid, which occur at the beginning and end of solidification and as a result of a change in the speed of solidification. The solute distributions in the transient regions are considered for the case of two solutes present in the melt. It is shown that, under certain conditions, p–n junctions may be produced in the transient regions of solidification in germanium or silicon melts containing two suitable solutes.