A system enables high-frequency communication between an external communication device and one or more implantable medical devices. The system implements a communication protocol in which the external communication device interrogates any implantable medical devices within range to establish one-to-one communication links for purposes of exchanging data and/or programming the medical devices.

Frequency agile telemetry system for implantable medical device

Magnetic recording media comprising an ordered, ultra-high density array of 500 Å diameter circular magnetic thin film islands on a substrate. The magnetic material supports magnetization perpendicular to the film plan, and each circular island comprises a single magnetic domain and a single information storage bit. An areal bit density of 10 11 bits/in 2 can be achieved by such an array. The magnetic array is generated using a single level mask comprised of a self-ordering polymer array, either an array of polymer spheres or a regular array of polymeric blocks in a phase-separating polymer film.

High density magnetic information storage medium

A magnetoresistive head includes an underlayer composed of one of Ni and NiFe alloy and at least one additive selected from the group consisting of Cr, Nb, Rh, and Pd. An anti-ferromagnetic layer is formed on the underlayer, and a first ferromagnetic layer is formed on the anti-ferromagnetic layer. The magnetic head also includes a nonmagnetic layer formed on the first ferromagnetic layer, and a second ferromagnetic layer formed on the nonmagnetic layer.

Magnetoresistive head with improved underlayer

A thin film magnetic structure, magnetic devices, and method of producing the same, wherein (110) textured, symmetry broken body centered cubic or body centered cubic derivative crystalline structures epitaxially grown on hexagonal shaped templates, in the presence of a symmetry breaking mechanism is provided to promote oriented uniaxial magnetic properties from a series of successively deposited film layers, result in new oriented magnetic layer structures and microstructures and thus improved magnetic devices and device performance

Magnetic material structures, devices and methods

The invention is embodied in an anisotropic, soft magnetic thin film article comprising a cobalt-iron-chromium-nitrogen (Co--Fe--Cr--N) alloy. The thin film is formed such that the alloy has a relatively high saturation magnetization (4πMs), e.g., greater than approximately 8 kilogauss (kG), a relatively low coercivity (Hc), e.g., less than approximately 2.0 oersteds (Oe), a relatively high squareness ratio (Mr /Ms), e.g., greater than approximately 0.90, and a relatively high anisotropy field (Hk), e.g., greater than approximately 20 Oe, in an as-deposited condition or, alternatively, with a relatively low temperature treatment, e.g., below approximately 300° Celsius. The inventive films are suitable for use in electromagnetic devices, e.g., in microtransformer cores, inductor cores and in magnetic read-write heads.

Article comprising anisotropic Co-Fe-Cr-N soft magnetic thin films

A soft magnetic thin micro-crystalline film of FeT b N c (at %) wherein T is at least one of Zr, Hf, Ti, Nb, Ta, V, Mo and W, and 0<b<20 and 0<c<22 except the range of b≦7.5 and c≦5, shows low coercivity Hc of 80-400 Am -1 (1-5 Oe) which is stable upon heating at elevated temperature for glass bonding. This film is produced by crystallizing an amorphous alloy film of the similar composition at 350°-650° C. to a crystal grain size up to 30 nm to provide uniaxial anisotropy and increased magnetic permeability at higher frequency. It can also provide low magnetostriction around γs=0. Composite magnetic head is made using this thin film. Diffusion preventive SiO 2 layer disposed between ferrite core and this thin film in the magnetic head prevents an interdiffusion layer and suppress beat in the output signal.

Soft magnetic thin film, method for preparing same and magnetic head

Uniaxially oriented soft magnetic thin film consists essentially of 1 to 15 atomic percent of Co and/or Ni, and the balance being Fe, and has a crystal structure of a body-centered cubic system, wherein the film is oriented substantially in the [111] direction and the absolute value of the saturation magnetostriction λ f of the film is not more than 5×10 -6 . The film has low coercivity 1 Oe or less and high magnetic permeability maintaining high saturation magnetic flux density of 18 kG or more. λ f reaches zero and is adjustable. Addition of 0.2 to 20 atomic percent of Ru, Mn, Cr and/or V increases wear resistance. The film is formed by deposition on {111} plane of GaAs substrate, or on c-plane of hexagonal B 8 stracture.

Soft magnetic thin film

A composite magnetic head comprises a pair of magnetic core halves each including a core block formed of an oxide magnetic material and a soft magnetic thin film disposed on said core block interposed with a reaction inhibiting layer, said core halves abutting to each other so that a magnetic gap is defined between the ends of said soft magnetic thin films. The magnetic head has a size relation bcd/a≦0.2×10 -10 m 2 wherein a is a gap length, measured along the proceeding direction of a magnetic recording medium, c a gap depth, d a gap width as measured along the track width and b is a thickness of said reaction inhibiting layer. Wavy (beat) noise of output signal due to the psuedo gap produced by the reaction inhibiting layer is effectively suppressed.

Composite magnetic head

A soft magnetic thin micro-crystalline film of FeT b N c (at %) wherein T is at least one of Zr, Hf, Ti, Nb, Ta, V, Mo and W, and 0<b≦20 and 0<c≦22 except the range of b≦7.5 and c≦5, exhibits low coercivity Hc of 80-400 Am -1 (1-5 Oe) which is stable upon heating at elevated temperature for glass bonding. This film is produced by crystallizing an amorphous alloy film of the similar composition at 350°-650° C. to a crystal grain size up to 30 nm to provide uniaxial anisotropy and increased magnetic permeability at higher frequency. It can also provide low magnetostriction around λs=0. Composite magnetic head is made using this thin film. Diffusion preventive SiO 2 layer disposed between ferrite core and this thin film in the magnetic head prevents an interdiffusion layer and suppress beat in the output signal.

Method for preparing same and magnetic head

A soft magnetic thin micro-crystalline film of FeaBbNc (at %) wherein B is at least one of Zr, Hf, Ti, Nb, Ta, V, Mo and W, and 0<b≦20 and 0<c≦22 except the range of b≦7.5 and c≦5, shows low coercivity Hc of 80-400 Am−1 (1-5 Oe) which is stable upon heating at elevated temperature for glass bonding. This film is produced by crystallizing an amorphous alloy film of the similar composition at 350-650° C. to a crystal grain size up to 30 nm to provide uniaxial anisotropy and increased magnetic permeability at higher frequency. It can also provide low magnetostriction around λs=0. Composite magnetic head is made using this thin film. Diffusion preventive SiO2 layer disposed between ferrite core and this thin film in the magnetic head prevents an interdiffusion layer and suppress beat in the output signal.

Osamu Shimizu

Papers

Soft magnetic thin film, method for preparing same and magnetic head

Soft magnetic thin film

Composite magnetic head

Method for preparing same and magnetic head

Method for preparing a magnetic thin film