Akita University

Showa Denko K.k.

Japan Science and Technology Agency

Osaka University

Hitoshi Saito

Satoru Yoshimura

Shunji Ishio

Takashi Hasegawa

Iwao Okamoto

Ryoichi Nakatani

Yukinori Kinoshita

Hikaru Nomura

Naoya Yamamoto

A magnetic field measuring device including: a vibrational probe unit having a probe that includes one or more material(s) whose intensity of magnetization is proportionate to an external magnetic field, a mechanical vibration source for the probe; a vibration detector detecting a vibration frequency and amplitude of the probe; an alternating-current magnetic field generator applying to the probe an alternating-current magnetic field; a direct-current external magnetic field generator applying a direct-current external magnetic field to the probe; a frequency modulation detector detecting frequency modulation occurring to the mechanical vibration of the probe; a direct-current external magnetic field controller adjusting the intensity of the direct-current external magnetic field applied to the probe; and a direct-current magnetic field determination unit determining a value of the direct-current magnetic field originating from a specimen.

Magnetic field value measuring device and method for measuring magnetic field value

A magnetic profile measuring device which scans a space where an alternating-current magnetic field exists by a magnetized probe on a tip of a driven cantilever, detects vibration of the cantilever, and generates an image of magnetic field distribution of the space, the device including: the cantilever having the probe equipped on the tip thereof; a driver driving the cantilever; a vibration sensor detecting vibration of the probe wherein the driven vibration of the cantilever is frequency-modulated by the alternating-current magnetic field; a demodulator demodulating from a detection signal of the vibration sensor a magnetic signal corresponding to an alternating-current magnetic field; a scanning mechanism; a data storage storing an initial data for each coordinate of the space; a modified data generator recalling the initial data from the data storage and generating a plurality of data by modifying the phase of the initial data; and an image display device.

Magnetic profile measuring device and method for measuring magnetic profile for alternating-current magnetic field

An electric field writing magnetic storage device including: a rotatable disk including a substrate and a magnetic recording film provided on a surface of the substrate, the magnetic recording film including at least one ferromagnetic and ferroelectric layer; a writing device writing information into the magnetic recording film by means of an electric field, the writing device including a writing electrode generating a dielectric flux between the writing electrode and the substrate by having electric potential to the substrate; and a writing circuit choosing one electric potential among plurality of electric potential level and applying the chosen one electric potential to the writing electrode in every operation of writing information, wherein the dielectric flux generated according to the electric potential applied to the writing electrode by the writing circuit magnetizes the ferromagnetic and ferroelectric layer in a specific direction.

Electric field writing magnetic storage device

A magnetic-field-observation device and method for measuring magnetic force near a magnetic material specimen's surface with high resolution and detecting the polarity of the magnetic pole of specimen's surface. The device including: a probe; excitation mechanism that excites it; scanning mechanism that relatively moves the probe and specimen; alternating magnetic field generation mechanism to make the probe periodically undergo magnetization reversal and apply thereto an alternating magnetic field having magnitude not making the specimen undergo magnetization reversal; and modulation measurement mechanism for measuring degree of periodical frequency modulation of the probe's oscillation caused by its apparent spring constant periodically changed by force of periodically changed intensity and applied to the probe by alternating force through magnetic interaction between magnetizations of the probe and specimen, by frequency demodulation or by measuring intensity of one sideband wave spectrum among spectrums generated by the frequency modulation. The method performed using the device.

Magnetic field observation device and magnetic field observation method

Provided are a surface state measuring device which can measure an alternating force of an arbitrary frequency and which is excellent in spatial resolution, and a surface state measuring method using the device. This surface state measuring device measures the surface state of a sample by detecting the modulation of the oscillation of a probe arranged above the sample. The measuring device comprises: a cantilever having a probe near a free end; an excitation mechanism for exciting the cantilever; a scanning mechanism for making the probe scan the sample by moving the probe and the sample relative to each other; and alternating force generator for generating an alternating force of an arbitrary frequency in a space; and a modulation measuring mechanism for measuring the degree of frequency modulation or amplitude modulation of the oscillations of the probe, which are generated by the alternating force.

Surface state measuring device, and surface state measuring method using the device

A magnetic recording medium for use in digital magnetic recording, which comprises a nonmagnetic substrate having deposited thereon a magnetic layer, wherein with respect to the in-plane direction, the magnetic recording layer comprises a plurality of ferromagnetic regions separated from each other by an antiferromagnetic region. A production method of the magnetic recording medium and a magnetic disc apparatus are also disclosed.

Magnetic recording medium, production method thereof and magnetic disc apparatus

A coersive force distribution analyzing, apparatus applies a magnetic field substantially perpendicularly to a sample including a perpendicularly magnetically recordable magnetic thin film. While tow-dimensionally moving the sample, the coersive force distribution analyzing apparatus generates a magnetic flux detection signal in response to a leakage flux generated in a magnetic domain on a sample surface. The apparatus applies, to the sample, a first external magnetic field and a second external magnetic field respectively corresponding to a first threshold and a second threshold selected from a hysteresis characteristic corresponding to average magnetization of the sample. This results in first magnetic domain image data and second magnetic domain image data. The apparatus uses the first and second thresholds to binarize the first and second image data to generate a first coersive force distribution pattern corresponding to the difference between the binarized first and second image data.

Growing community of inventors

Akita, Japan

Hitoshi Saito