Commissariat a L'energie Atomique

Centre National De La Recherche Scientifique

Other

Centre National Detudes Spatiales

Institut Polytechnique De Grenoble

Commissarat a L&prime;energie Atomique

Thierry Duffar

Pierre Dusserre

Jean-Paul Garandet

Nathalie Giacometti

Jean-Philippe Nabot

Jean Delepine

Gilbert Vian

Annie Fournier-Gagnoud

J&uuml;rgen Wollweber

Jean-Louis Santailler

V&eacute;ronique Chevrier

Jacques Abadie

Bernard Wales

The disclosure relates to a method for the crystallogenesis of a material that is electrically conducting at the molten state, by drawing from a molten mass of the material in a crucible, that comprises: progressively subjecting the molten material to a decreasing temperature so that a liquid-solid interface is formed; controlling the flatness of the liquid-solid interface of the material; subjecting the molten material, before and during solidification, to an electromagnetic kneading; the method including that the electromagnetic kneading is obtained by applying an alternating magnetic field. The disclosure also relates to a device for implementing the method.

Method for the crystallogenesis of a material electrically conducting in the molten state

A device for manufacturing a single-crystal solid phase by solidification of a liquid phase, comprising: a crucible capable of containing the solid phase and the liquid phase, the liquid phase being in contact with the crucible and the solid phase being separated from the crucible by an interstice; and a heating mechanism for heating the liquid phase capable of creating a thermal gradient at the level of an interface between the liquid phase and the solid phase, electromagnetic field generation, distinct from the heating mechanism, for applying an electromagnetic pressure on the junction surface of the liquid phase at the level of the interface comprising at least one spiral surrounding the crucible, and placed opposite to the area in which the interface forms in operation.

Method and device for producting monocrystals

A process produces a crystal of a material with non-congruent melting using at least one first element and a second element. The process includes (a) placing, in a vertical alignment and maintaining under a controlled atmosphere, a bar of the first element gripped between a lower bar and an upper bar made out of the material, (b) transforming the bar of the first element into a floating zone by heating to a temperature that avoids the evaporation of the first element, the heating being obtained by heating means that provides a temperature gradient in the floating zone so that the lower face of the upper bar appears as a cold face, and (c) contra-rotating the lower and upper bars around the alignment axis and moving the whole bar assembly upwards in relation to the heating means in order to obtain the crystal on the cold face by growth in solution.

Growth in solution in a float zone of crystals of a compound or an alloy

The device according to invention comprises an ampoule ( ) at the bottom of a crucible ( ) for crystal growing by progressive solidification of a liquid, and a specific means of heating ( ) to adjust the temperature of the volume of this gas pocket and establish an overpressure at the bottom of the crucible compared to the top in order to ensure a contraction of the crystal ( ) at the moment of its solidification and to avoid defects in the crystals. By eliminating a pressure regulating circuit linking these two extreme regions in order to establish the overpressure directly, the lay out is considerably simplified and at the same time avoids condensations of the vaporised portions of the crystal in the pipes.

Crystal growth device and method

A method for manufacturing a solid single crystal of an electrically conductive material by pulling from a molten mass of this material, the material presenting atom clusters at melt. The method includes: a melt stage so as to obtain a molten mass, the melt stage procuring a colder zone of the molten mass, from which the single crystal will be pulled, and a hotter zone having sufficient temperature to melt the atom clusters; a stage of application to the molten mass of a rotating magnetic field allowing the atom clusters to be displaced from the colder zone to the hotter zone; and a stage of growth by pulling of the single crystal after the atom clusters have been displaced from the colder zone to the hotter zone.

Crystallogenesis method with magnetic field

A piston-activated crystal-growing apparatus includes a crucible for containing a seed and a solidifiable liquid covering the seed. In operation, thermal gradient is established in the crucible, and a piston moves within the crucible in the direction of the crystal.

Piston-activated crystal-growing apparatus

The material of the crystal (2) formed by solidification is deposited in a crucible (1), whose wall is perforated by two ducts for the injection of pressure at different heights (6, 7). A differential pressure is created between the two ducts, the pressure of the lower duct (7) being higher by a value roughly equal to the hydrostatic pressure of the remaining liquid (3), so that a clearance (5) is spontaneously formed between the crystal (2) and the crucible (1) and problems caused by differential thermal contractions on cooling are avoided.

Crystallogenesis device and process

This device is for the tight crossing of a partition or bulkhead by a mobile member. The object of the invention is to supply a device permitting the transfer of simultaneous, complex mechanical movements through a tight partition, whilst maintaining the seal of the partition. This object is achieved with the aid of a device having at least one shell or sleeve (4) mounted on a partition so as to pivot about a pivoting axis perpendicular to the crossing axis of the partition by the member and the displacement direction of the member. The member passes in the interior of the sleeve. A plate (12) is tightly traversed by the member (10) and mobile with the member for its displacements in the displacement direction. First and second tight membranes (14 and 16) tightly connect the plate (12)/sleeve (4) and sleeve (4)/partition (8).

Growing community of inventors

Grenoble, France

Thierry Duffar