Effects of impurity (N2) on thermo-solutal convection during the physical vapor transport processes of mercurous chloride

Abstract

For Ar = 5, Pr = 1.18, Le = 0.15, Pe = 2.89, Cv = 1.06, PB = 20 Torr, the effects of impurity (N2) on thermally and solutally buoyancy-driven convection (Grt = 3.46 × 104and Grs = 6.02 × 105, respectively) are theoretically investigated for further understanding and insight into an essence of thermo-solutal convection occurring in the vapor phase during the physical vapor transport. For 10 K ≤ ΔT ≤ 50 K, the crystal growth rates are intimately related and linearly proportional to a temperature difference between the source and crystal region which is a driving force for thermally buoyancy？driven convection. Moreover, both the dimensionless Peclet number (Pe) and dimensional maximum velocity magnitudes are directly and linearly proportional to ΔT. The growth rate is second order-exponentially decayed for 2 ≤ Ar ≤ 5. This is related to a finding that the effects of side walls tend to stabilize the thermo-solutal convection in the growth reactor. Finally, the growth rate is found to be first order exponentially decayed for 10 ≤ PB≤ 200 Torr.