During optically heated float-zone crystal growth processing, a cylindrical melting zone forms from a polycrystalline rod by lateral heating, then re-solidifies into single crystal rod. Thermocapillary forces drive a flow in the melt region. This base flow is susceptible to instabilities, which lead to nonuniformities and defects in the crystal. In order to minimize these imperfections, a magnetic field is employed to damp the base flow within the melt region. Modeling this base flow has proven challenging, and two representations are discussed here. The float-zone crystal growth base flow under the influence of a constant magnetic field and neglecting buoyancy is investigated with a full-zone model. The flow field and temperature distributions are calculated by a steady state, axisymmetric spectral collocation method using Chebyshev polynomials as basis functions. A 2nd order vorticity transport representation is compared with a 4th order stream function formulation. The results show high consistency between the models.

This content is only available via PDF.
You do not currently have access to this content.