Float zone growth of silicon was performed using a ring-shaped radio-frequency (RF) inductor of 600 kHz. The grown crystals were analyzed with respect to interface curvature and microsegregation, i.e. the width, the frequency, and the intensity of convectively induced dopant inhomogeneities. The results were compared to crystals grown in a radiation-heated growth facility. The influence of a rotating magnetic field (RMF) with B-max = 7 mT and f(max) = 300 Hz on the growth was investigated. The axial temperature profile was determined by a pyrometer (spot size: 0.7 mm, working distance: 140 mm). The temperature gradient at the solid-liquid interface amounts to 275 K/cm, which is about a factor of 3 larger than for the radiation-heated process. Convective temperature fluctuations, measured at the free melt surface, reached fluctuation amplitudes of 5 K (radiation-heated case: 1 K), with a pronounced frequency distribution between 2 and 4 Hz and around 8 Hz, respectively (radiation-heated zones: < 0.4 Hz). The spacing of the dopant striations agrees well with the main part of the temperature fluctuations and reveals a maximum between 2 and 4 Hz. Applying an RMF, the dopant striations can be suppressed considerably, similar to the results obtained in radiation-heated crystals. The required RMF intensity is higher in the RF-case. The interface deflection is reduced due to the rotating field. The azimuthal flow velocity generated by the rotating magnetic field, was measured by tracer observation, the flow increases linearly with the Taylor number and reaches a velocity of 12 cm/s under a field strength of B = 7 mT/f(B) = 300 Hz. (C) 2003 Elsevier B.V. All rights reserved.