Numerical analysis of transport phenomena in Y–Ba–Cu–O melt during growth of superconducting crystal Y123 by Czochralski method

Abstract

In 1993, at the Superconductivity Research Laboratory (SRL), International Superconductivity Technology Centre (ISTEC), in Tokyo, continuous growth of large single crystals of YBa 2 Cu 3 O 7− x (Y123) was achieved by the application of a modified Czochralski method. This paper presents the numerical computations of the flow, thermal and Y concentration fields in the Ba–Cu–O melt for Y123 single crystal growth by this modified method. The finite volume method was used to calculate the fluid flow, heat transfer and yttrium distribution in the melt with staggered numerical grid. The flow in the melt was modelled as an incompressible Newtonian and Boussinesque fluid. Calculations are presented for a combined flow regime of buoyancy-driven natural convection and crystal-rotation-driven forced convection.