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公开(公告)号：GB1283690A
公开(公告)日：1972-08-02
申请号：GB5195670
申请日：1970-11-02
Applicant: IBM
Abstract: 1283690 Superconductor devices INTERNATIONAL BUSINESS MACHINES CORP 2 Nov 1970 [12 Nov l969] 51956/70 Heading HlK In a tunnelling device having a pair of superconductive electrodes separated by a barrier, at least one of the electrodes is single crystalline. The device may form a Josephson junction. The devices are produced by depositing the first electrode on a single crystal substrate, for example by RF or DC sputtering, thermal evaporation, or chemical vapour transport. The barrier layer is then formed for example by thermal oxidation, anodization, ion implantation, sputtering, or evaporation, and may be monocrystalline or amorphous, and the second electrode is then deposited. It is stated that the top electrode may be monocrystalline even if the barrier layer is amorphous providing the latter layer is thin. Examples of in-line and cross-film tunnelling cryotrons are described. A triode structure comprising one electrode separated from two further electrodes by tunnelling junctions (Fig. 6) and a known cryogenic memory array (Fig. 8) modified by utilizing monocrystalline electrodes and barrier layers are also described. The Specification contains a list of materials suitable for the substrate, electrodes and barrier layer.
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公开(公告)号：DE2650484A1
公开(公告)日：1977-06-08
申请号：DE2650484
申请日：1976-11-04
Applicant: IBM
Abstract: A magnetoresistive permalloy film is deposited upon a substrate and coated with a separating layer composed of titanium or a similar high resistivity, conductive material. A soft biasing layer of a material such as permalloy or a hard biasing material such as cobalt chromium is deposited upon the separating layer to complete a sandwich. All layers are coextensive in outline because their outlines are formed by a single etching step.
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公开(公告)号：DE2358875A1
公开(公告)日：1974-06-27
申请号：DE2358875
申请日：1973-11-27
Applicant: IBM
Inventor： BAJOREK CHRISTOPHER HENRY , KRONGELB SOL , MAYADAS ASHOK FRANK
IPC: G11C11/14 , G01R33/09 , G11B5/39 , G11B5/72 , G11C19/08 , H01C1/034 , H01C10/10 , H01F41/32 , H01L43/08 , G11B5/30
Abstract: 1391150 Magnetic heads INTERNATIONAL BUSINESS MACHINES CORP 12 Oct 1973 [30 Nov 1972] 47709/73 Heading G5R [Also in Division H3] Decrease of sensitivity due to oxidization of a magnetoresistive thin film magnetic bubble sensor or magnetic tape reading head is prevented by an overlay of Al 2 O 3 or Si 3 N 4 . The magnetoresistive material may be permalloy, or an alloy of Ni-Fe, Ni-Fe-Co, Ni-Co or Fe-Co, and have a thickness of between 200 and 1000. The overlay may be of twice this thickness. As applied to sensing magnetic bubbles 4, Fig. 1, in a magnetic plate 2, the sensor consists of a permalloy element 10 having an easy axis of magnetization in the direction of current flow from a source 12 through the element. The presence of a magnetic bubble changes the element resistance which is detected by the change of voltage across the source. A layer of a dielectric material S and a sputtered layer 18 of Al 2 O 3 or Si 3 N 4 extend over the magnetic plate and the magnetoresistive element. Similar layers are applied over the reading head 20, Fig. 2, of a moving magnetic tape 22, the magnetoresistive sensor 10 being similar to that shown in Fig. 1.
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公开(公告)号：DE2313380A1
公开(公告)日：1974-01-24
申请号：DE2313380
申请日：1973-03-13
Applicant: IBM
Inventor： HOLTZBERG FREDERIC , MAYADAS ASHOK FRANK , THOMPSON WILLIAM ALEXANDER , MOLNAR STEPHAN VON
Abstract: 1400961 Magnetic field detection INTERNATIONAL BUSINESS MACHINES CORP 14 Feb 1973 [23 June 1972] 7130/73 Heading G1N [Also in Divisions H1 and H3] A device for sensing the magnetic field associated with a magnetic bubble domain, e.g. representing information, comprises a tunnel junction whose resistance changes with the field magnitude. When the field intercepts the junction the Fermi level of one or more of the materials forming the junction changes, altering the tunnel barrier height and hence altering the junction resistance; this latter change is detected by connecting a constant current or voltage across the junction and measuring the voltage or current respectively across the device. Fig. 7 shows part of a bubble domain sheet 10, on which are two electrodes 20A, 20B separated by a barrier material 18. If desired, the sheet 10 may be part of a magnetic disc or tape for non- bubble applications. The barrier 18, which is preferably less than 100Š thick, may be an insulator, a magnetic insulator, or a magnetic semi-conductor. In Fig. 8 a Schottky barrier is formed between a metal conductor 20A and a semi-conductor or magnetic semi-conductor 18. Fig. 9A shows a double Schottky barrier, a pair of metal contacts 20A, 20B and a pair of semiconductor or magnetic semi-conductor layers S1, S2 being used. The semi-conductors are preferably the same material, e.g. EuS, but have different doping levels. In Fig. 10A, (not shown), an insulating layer is placed between the two semiconductor layers of Fig. 9A, this insulating layer forming the tunnel barrier. In Fig. 11, (not shown) an insulating layer is used to form the barrier between a metal contact and a semi-conductor or magnetic semi-conductor layer. In Fig. 12 the magnetic domain sheet itself, which carries a domain propagating overlay 44 of conventional form, acts as a magnetic insulator between metal electrodes 20A, 20B. The sheet should be less than 100Š thick. Materials: the insulators may be oxides or lightly doped semi-conductors; the metal electrodes may be a highly doped semi-conductor (>10 20 carriers per cc) or, e.g. Indium. The embodiments using semi-conductors preferably employ materials doped in the range 10 17 -10 21 carriers per cc: magnetic semi-conductors which are usable are EuS, EuO, doped with trivalent rare earths or excess Eu to a level around 10 19 carriers per cc. CdCr 2 Se is an alternative magnetic semi-conductor. A magnetic conductor such as Al-Al 2 O 3 -Fe may be used as the metal electrodes, preferably near its Curie point. Magnetic insulators may be undoped EuS or EuO, or garnets. Example: A Schottky barrier between Indium and EuS is formed from single crystals of EuS having sulphur vacancies grown by melting and regrowth in a tungsten crucible. The crystal is vacuum cleaved and the Indium deposited during cleaving to avoid contamination. The second electrode is formed by diffusing a La-Ag alloy into the crystal. In these devices domain movement is not necessary to detection. Any domain having a field component along the sheet may be detected. The detector is the same order of size as the domain and is sensitive enough to detect sub-micron domains.
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