The influence of a rotating magnetic field (RMF) on the vertical gradient freeze (VGF) growth of Ga-doped Ge is studied numerically using the program CrysVun(++). On the basis of a global, time-dependent simulation of the VGF process including the melt flow a simple approach to estimate the solute segregation is presented. It is shown that the radial as well as the axial segregation can be improved by applying a RMF. (c) 2006 Elsevier B.V. All rights reserved.