Abstract: A method is provided for preparing a surface of a GaAs substrate (001) such that it can receive a ferromagnetic semiconductor deposited by epitaxy, as well as a substrate thus prepared, method for manufacturing one such semiconductor deposited on the substrate, the resulting semiconductor, and uses thereof. The preparation method renders the surface capable of receiving an epitaxially deposited ferromagnetic semiconductor which may include semiconductors from groups III-V, IV and II-VI of the periodic table, with the exception of GaAs, and which also includes at least one magnetic element of manganese, iron, cobalt, nickel and chromium. The method includes vacuum deoxidation of the surface under a reduced germanium-based flux such that, following desorption of the arsenic and gallium oxide from the said surface, the latter has a single-domain 2×1 reconstruction and is sufficiently planar and arsenic-depleted to prevent any diffusion of arsenic from the substrate to the subsequently deposited semiconductor.

Abstract: The inventive ferromagnetic semiconductor comprises at least one magnetic element selected from the group consisting of Mn, Fe, Co, Ni and Cr, and has a Curie temperature which is equal to or higher than 350 K, and advantageously 400 K or higher. The semiconductor has a matrix which is depleted in magnetic element(s) and contains a discontinuous phase which is formed from columns, enriched with magnetic elements, and is ferromagnetic up to said Curie temperature, in such a way as to generate a lateral modulation of the composition of the semiconductor in the plane of the thin layer. Also disclosed is a method for the production of the semiconductor, a diode-type electronic component for the injection or collection of spins into or from another semiconductor respectively, or an electronic component which is sensitive to a magnetic field, and uses of the semiconductor relating to such a component.

Abstract: The invention concerns a magnetic field-sensitive component, a magnetic field sensing device and a memory structure each incorporating said component, and a method for detecting a magnetic field using said component. A component according to the invention comprises: at least one diluted magnetic semiconductor, first means for generating an electric current in said semiconductor along one predetermined direction, and second means for producing a signal representing a Hall voltage transverse to said direction, and it is so designed that the semiconductor is selected from the group consisting of II/VI and IV/IV type semiconductors and comprises a zone sensitive to said field which forms all or part of a magnetic quantum well, wherein are confined current carriers incorporated by doping in the semiconductor and inducing in said well ferromagnetic exchange interactions.

Abstract: The magnetic device comprises a magnetic device comprising a magnetoresistive tunnel junction (100), itself comprising: a reference magnetic layer (120) having magnetization in a direction that is fixed; a storage magnetic layer (110) having magnetization in a direction that is variable; and an intermediate layer (130) acting as a tunnel barrier that is essentially semiconductor or electrically insulating and that separates the reference magnetic layer (120) from the storage magnetic layer (110). The potential profile of the intermediate layer (130) is asymmetrical across the thickness of said layer (130) so as to produce a current response that is asymmetrical as a function of the applied voltage. The device is applicable to magnetic random access memories.

Abstract: The invention concerns a magnetic field-sensitive component, a magnetic field sensing device and a memory structure each incorporating said component, and a method for detecting a magnetic field using said component. A component according to the invention comprises: at least one diluted magnetic semiconductor, first means for generating an electric current in said semiconductor along one predetermined direction, and second means for producing a signal representing a Hall voltage transverse to said direction, and it is so designed that the semiconductor is selected from the group consisting of II/VI and IV/IV type semiconductors and comprises a zone sensitive to said field which forms all or part of a magnetic quantum well, wherein are confined current carriers incorporated by doping in the semiconductor and inducing in said well ferromagnetic exchange interactions.

Abstract: The magnetic device comprises a magnetic device comprising a magnetoresistive tunnel junction (100), itself comprising: a reference magnetic layer (120) having magnetization in a direction that is fixed; a storage magnetic layer (110) having magnetization in a direction that is variable; and an intermediate layer (130) acting as a tunnel barrier that is essentially semiconductor or electrically insulating and that separates the reference magnetic layer (120) from the storage magnetic layer (110). The potential profile of the intermediate layer (130) is asymmetrical across the thickness of said layer (130) so as to produce a current response that is asymmetrical as a function of the applied voltage. The device is applicable to magnetic random access memories.

Abstract: The inventive ferromagnetic semiconductor comprises at least one magnetic element selected from the group consisting of Mn, Fe, Co, Ni and Cr, and has a Curie temperature which is equal to or higher than 350 K, and advantageously 400 K or higher. The semiconductor has a matrix which is depleted in magnetic element(s) and contains a discontinuous phase which is formed from columns, enriched with magnetic elements, and is ferromagnetic up to said Curie temperature, in such a way as to generate a lateral modulation of the composition of the semiconductor in the plane of the thin layer. Also disclosed is a method for the production of the semiconductor, a diode-type electronic component for the injection or collection of spins into or from another semiconductor respectively, or an electronic component which is sensitive to a magnetic field, and uses of the semiconductor relating to such a component.