Magnetic core

About: Magnetic core is a research topic. Over the lifetime, 30011 publications have been published within this topic receiving 155247 citations.

Thin film magnetic head, magnetoresistance effect magnetic head and composite magnetic head

Abstract: A thin-film magnetic head, a magnetoresistance effect magnetic head and an MR inductive head are disclosed. The thin-film magnetic head has one of thin-film magnetic cores stacked on a substrate and formed of two magnetic films and a non-magnetic film held between them, with a current flowing through the thin-film magnetic core in the direction of hard axis thereof. The magnetoresistance effect magnetic head has one of a pair of shield cores having a magnetoresistive element between them formed of two magnetic films and a non-magnetic film held between them, the magnetoresistive element being electrically connected to the shield core, with a sense current flowing through the shield core. The current flowing through the one shield core via the magnetoresistive element is preferably an AC of decrement amplitude for demagnetizing the shield core along with a DC sense current. Also, this current preferably flows in the direction of hard axis of the shield core so that magnetic properties of the shield core are stabilized or demagnetized by the magnetic field generated in the direction of easy axis. The MR inductive head has a second thin-film magnetic core as a common magnetic body of an MR head and an inductive head on one substrate, formed of two magnetic films and a non-magnetic film held between them, with a current flowing through the second thin-film magnetic core in the direction of hard axis thereof.

Additive Manufacturing of Toroid Inductor for Power Electronics Applications

Abstract: To increase power density and simplify the process of integrating magnetic components to power electronics circuits, a commercial multiextruder paste-extrusion three-dimensional (3-D) printer was used to process both metal and magnetic pastes into 3-D structures of magnetic components. A magnetic-filled-benzocyclobutene composite, termed poly-mag paste, was formulated and used as a magnetic core feedstock for the printer, and a commercial nanosilver paste was used as a conductive winding feedstock for the printer. A toroid inductor was 3-D printed by using metal and magnetic pastes, and it was cured at 250 °C for a half hour without any external pressure to form the structure. The inductance of the 3-D-printed toroid inductor was measured to be 167–143 nH in the frequency range of 1 kHz to 3 MHz. The dc resistance of the winding was 0.1 Ω. These results are in good agreement with a finite-element analysis simulation. Both the winding and core magnetic properties can be improved by adjusting the feed paste's formulations and flow characteristics, and by fine tuning the printer parameters, such as motor speeds, extrusion rate, and nozzle sizes.

An all-solid-state pulsed power generator using a high-speed gate-turn-off thyristor and a saturable transformer

Abstract: Recently, high-repetition-rate pulsed power generators using a magnetic pulse compression circuit (MPC) and semiconductor switches have been developed. We have developed a new all-solid-state pulsed power generator for use with a high-repetition-rate excimer laser and in an ozonizer. The all-solid-state generator consists of a semiconductor switch and an MPC with saturable inductors (SI) and a saturable transformer (ST). The semiconductor switch is a high-speed gate-turn-off (GTO) thyristor. The switching speed of the GTO thyristor was improved, decreasing the switching loss. The ST with an Fe-based nanocrystalline magnetic core has two functions, those of step-up transformer and magnetic switch. The high-speed GTO thyristor and the new MPC can be used to realize a high-performance, simple all-solid-state pulsed power generator. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 140(4): 17–26, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.2006

Direct protein detection in the sample solution by monitoring rotational dynamics of nickel nanorods.

Abstract: The feasibility of a recently introduced homogeneous immunodiagnostic approach to directly detect analyte binding by optical observation of the hydrodynamic properties of magnetically rotated nanorods ("PlasMag") is demonstrated experimentally. Specifically, it is shown that the phase lag of the long axis of nickel nanorods (magnetic core parameters: length 182 nm, diameter 26 nm) with respect to externally applied rotating magnetic fields significantly increases on the adhesion of bovine serum albumin (BSA) protein to their surfaces. To validate these results, the amount of bound protein molecules is independently determined by analysis of the electrophoretic mobility of the nanorods. Furthermore, the data also demonstrate the applicability of recently developed empirical models based on numerical solutions of the Fokker-Planck equation for describing the dynamics of magnetic nanoparticles in rotating magnetic fields.

Integration of crossed anisotropy magnetic core into toroidal thin-film inductors

Abstract: A new approach to RF thin-film inductors with an integrated magnetic core has been investigated. A toroidal inductor design was realized in thin-film technology aiming at small-signal applications in the frequency range from 10 MHz to 1 GHz. The magnetic core consists of a multilayer of sputter deposited soft magnetic FeCoBSi. The individual magnetic films were deposited in a way to realize a crossed magnetic anisotropy in the core. High-frequency measurements of the multilayers already illustrated the advantages of the unique magnetic geometry. The influence and benefit of such a magnetic core on the toroid microinductor is discussed. The results show that such crossed anisotropy microinductors are a very promising alternative to common planar spiral inductors in the RF range.