Abstract: A method for the division of single crystals, in particular of GaAs, is provided in which a single crystal (1) to be cut into at least two parts and a cutting tool (2, 3; 8, 8a, 8b, 8c) are moved relative to one another in a direction of advancement (V) and wherein the single crystal (1) is oriented in such a way that a specified crystallographic orientation (K) lies in the cutting plane (T), characterized in that an angle (?) between the specified crystallographic direction (K) and the direction of advancement (V) is chosen in such a way that forces which act on the cutting tool during cutting in a direction at right angles to the cutting plane compensate one another.

Abstract: An apparatus and a method for determining the orientation of a crystallographic plane (100) relative to a crystal surface (2) are provided, in which the orientation is free from errors of adhesion of the crystal or contamination of the holders for the crystal. For this purpose, the angle which the crystal surface to be measured forms with a reference axis and the angle which the crystallographic plane forms with the reference axis are measured and subtracted. In a wire sawing apparatus with an X-Y positioning unit, next the desired correction is made with the aid of measurement of the orientation and at the same time the crystal is displaced in horizontal and vertical positions. As a result, there remains a further degree of freedom of rotation of the crystal in the cutting plane for achieving a cut which is free from forces perpendicular to the feed direction and wire direction, so that no tool deflection takes place or the cutting forces are minimal. Further, the precision of orientation is increased.

Abstract: An apparatus and a method for determining the orientation of a crystallographic plane (100) relative to a crystal surface (2) are provided, in which the orientation is free from errors of adhesion of the crystal or contamination of the holders for the crystal. For this purpose, the angle which the crystal surface to be measured forms with a reference axis and the angle which the crystallographic plane forms with the reference axis are measured and subtracted. In a wire sawing apparatus with an X-Y positioning unit, next the desired correction is made with the aid of measurement of the orientation and at the same time the crystal is displaced in horizontal and vertical positions. As a result, there remains a further degree of freedom of rotation of the crystal in the cutting plane for achieving a cut which is free from forces perpendicular to the feed direction and wire direction, so that no tool deflection takes place or the cutting forces are minimal. Further, the precision of orientation is increased.

Abstract: A method for the division of single crystals, in particular of GaAs, is provided in which a single crystal (1) to be cut into at least two parts and a cutting tool (2, 3; 8, 8a, 8b, 8c) are moved relative to one another in a direction of advancement (V) and wherein the single crystal (1) is oriented in such a way that a specified crystallographic orientation (K) lies in the cutting plane (T), characterised in that an angle (&rgr;) between the specified crystallographic direction (K) and the direction of advancement (V) is chosen in such a way that forces which act on the cutting tool during cutting in a direction at right angles to the cutting plane compensate one another.

Abstract: A device is made available for producing monocrystals, for example large-diameter gallium arsenide monocrystals, that has a cylindrical heating appliance with a floor heater (2) and a cover heater (3). The heating surfaces of the floor and the cover heater are considerably larger than the cross-sectional area of the monocrystal to be produced. In addition, an insulator (6) is planned for the reaction space that is designed to prevent a radial heat flow and the guarantee a strictly axial heat flow over the complete height of the reaction space between the cover heater (3) and the floor heater (2).

Abstract: A method and a device for the division of materials, in particular of single crystals, in particular by inner hole cutting is provided, with a cutting disk (2) having a concentric hole whose edge (3) forms a cutting edge and wherein the cutting disk (2) is rotatable about its central axis in order to cut the single crystal (1), a positioning device for positioning the single crystal (1) to be cut relative to the cutting disk in such a way that the cutting disk moves in rotating manner through the single crystal in order to separate off a part (1a) of the single crystal (1), and a device for the supply of coolant-lubricant onto the cutting disk (2), wherein the device (10) for the supply of coolant-lubricant is arranged in such a way that viewed in the direction of rotation it supplies the coolant-lubricant on the exit side behind the passage of the cutting disk (2) through the single crystal (1), and a device for the supply of compressed air (12).

Abstract: In a method and an apparatus for producing monocrystals, in particular of gallium arsenide monocrystals, the crystal growth is carried out with a thermal shock resistant nucleus which is freely standing within a nucleus channel and the interspace in the nucleus channel between the nucleus and the crucible is filled with liquid boric oxide.