Abstract: The present invention concerns a magnetroesistive sensor. In this sensor, the sensitive element is constituted by a monocrystalline magnetic metallic multilayer formed of a stack of layers of a magnetic material separated by layers of a non-magnetic material, the multilayer being constructed in such a way that the layers of magnetic material have antiferromagnetic type coupling and that of the transition between the antiparallel aligned state and the parallel aligned state occurs in a very short interval of the magnetic field.

Abstract: A device made with thin layers comprises at least two layers of materials having different electrical characteristics. At least one of the layers is superconductive. The superconductive layer comprises a rare earth (or yttrium) which is chosen so as to confer superconductive characteristics. The other layer has a constitution which differs from that of the superconductive layer, solely by the fact that the rare earth is different and confers different electrical properties.

Abstract: Disclosed is a magnetic reading head using the Hall effect. In this head, the active element comprises a substrate on which the following are epitaxially grown: a layer of a semiconductor material with high electron mobility and a magnetic metallic multilayer formed by stacked layers of magnetic materials and non-magnetic materials, the layer of semiconductor material and the multilayer being electrically insulated from each other. This head also has electrodes for current supply and Hall voltage detection that are in contact with the layer of semiconductor material. The disclosed device can be applied to the reading of magnetic recording media.

Abstract: The invention provides a method of forming thin layers of superconducting materials and a superconducting device. In accordance with the invention, such layers are formed by the epitaxial growth, on a substrate, of the different constituent elements by regulating the admission of the different constituents so as to obtain a superconducting layer whose mesh parameter substantially matches that of the substrate. Epitaxying may also be carried out directly from a superconducting material.