Linear magnetoresistance-effect sensor with semiconductor and ferrimagnetic layers and its application in a magnetic-domain detector
AssigneeThomson-CSF
InventorsPaul L. Meunier, Ernst Huijer, Manijeh Razeghi, Jean C. Lehureau
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Abstract
A magnetoresistance-effect sensor for use in a magnetic domain detector for reading data recorded on magnetic tapes or in magnetic bubble memories mainly consists of a layer of semiconductor material which carries a layer of ferrimagnetic material on one face and at least one pair of electrodes disposed along an axis OX on the other face, the layer of ferrimagnetic material being placed in proximity to the magnetic data carrier. A magnetic data item thus induces a magnetic field in the layer of semiconductor material in a direction OY perpendicular to the axis OX of the pair of electrodes.
Claims13
A linear magnetoresistance-effect sensor comprising a layer of semiconductor material provided to detect magnetic fields perpendicular to said layer of semiconductor material and having a first face and a second face, a layer of ferrimagnetic material exhibiting high anisotrophy provided to guide and transfer said magnetic fields to said semiconductor material by a scale factor substantially greater than one, thereby to increase an amount of an adjacent magnetic field which reached said semiconductor layer by magnetoresistance effect and increase sensitivity to detection of magnetic fields, said layer of ferrimagnetic material covering the first face of the layer of semiconductor material and constituting with said layer of semiconductor material a monocrystal, at least one pair of electrodes placed on the second face of the layer of semiconductor material.
A magnetic domain detector comprising a magnetic data carrier having at least one domain for inducing a magnetic field in a first predetermined direction, wherein said detector also comprises a sensor comprising:
- a layer of semiconductor material provided to detect magnetic fields perpendicular to said layer of semiconductor material and having a first and second face;
- a layer of ferrimagnetic material exhibiting high anisotropy provided to guide and transfer said magnetic fields to said semiconductor material by a scale factor substantially greater than one, thereby to increase an amount of an adjacent magnetic field which reaches said semiconductor layer by magnetoresistance effect and increase sensitivity to detection of magnetic fields, said layer of ferrimagnetic material deposited on the first face of the semiconductor material and constituting with said layer of semiconductor material a monocrystal;
- at least one pair of electrodes placed on the second face of the semiconductor material in a second direction;
- said sensor being arranged so as to ensure that the face which carries the layer of ferrimagnetic material is located in proximity to the magnetic data carrier and that the second direction of the two electrodes is perpendicular to the first direction of the magnetic field.
Dependencies are inferred from the claim text.