Abstract: Device for supporting a crystalline rod during crucible-free zone melting ich comprises a zone-drawing apparatus, a rotating shaft in said apparatus, means for fastening the shaft in the apparatus, a screw bolt mounted for rotation with the shaft, the top end of the screw bolt having a bore for receiving a seed crystal, two or more swivel arms mounted adjacent to the bore and capable of being opened and closed, a ring coaxially surrounding the bolt and means for vertically moving the ring.

Abstract: Process for polishing semiconductor surfaces, especially gallium phosphide urfaces, with an aqueous suspension of aluminum and/or gallium hydroxide precipitated from the elements by an alkaline compound at the pH value between 7.5 and 8, the suspension further containing an alkali hypochlorite in such an amount that in addition to 0.05-0.6 mol hydroxide per liter, the molar content of hypochlorite will be three to ten times that of the hydroxide; the surfaces are subjected to a buffing action with said suspension. The invention also relates to the polishing agent used in the process.