Magnetic domain transition controlled by distributed normal magnetic field for stepped magneto-impedance sensor

Article type: Research Article

Authors: Nakai, Tomoo^a

Affiliations: [a] Industrial Technology Institute, Miyagi Prefectural Government, Izumi-ku, Sendai, Japan E-mail: [email protected]

Correspondence: [*] Industrial Technology Institute, Miyagi Prefectural Government, 2-2 Akedori, Izumi-ku, Sendai, 981-3206, Japan. E-mail: [email protected]

Abstract: A thin-film magneto-impedance (MI) sensor has the unique property of step-like magneto-impedance change, in the case where the sensor has an in-plane uniaxial inclined easy axis. A domain observation shows that the step-like change is due to a magnetization transition within three states, such as longitudinal single domain with parallel state, the one with anti-parallel state and the inclined Landau-Lifshitz domain (ILLD). In a condition where the sensor has an easy axis of 70 degrees relative to the short side axis of the rectangular element, the transition is limited between the parallel and anti-parallel in spite of existing of stable ILLD. This paper reports a trial of control the magnetization transition from the single domain state to the ILLD state by controlling a normal field with canted angle distribution along the element position, which is aiming for realizing a low energy consumption sensor with inextinguishable memory function using a phenomenon of a magnetic domain transition for the use of sensor network.

Keywords: Magnetic domain, magneto-impedance, normal field, stepped GMI, thin film

DOI: 10.3233/JAE-171005

Journal: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 1, pp. 105-114, 2019