著者

能崎 幸雄 松山 公秀 小野 輝男 宮島 英紀

出版者

公益社団法人 日本磁気学会

雑誌

日本応用磁気学会誌 (ISSN:02850192)

巻号頁・発行日

vol.23, no.4_2, pp.1121-1124, 1999 (Released:2007-03-20)

参考文献数

3

被引用文献数

1 1

---

The micromagnetic structure of the 180° domain wall in submicron-size ferromagnetic Co wires was investigated by means of magnetic force microscopy. The wall width δ (∼μm) observed in Co wire is much larger than that observed in Co films of the same thickness. From micromagnetic calculation using the Landau-Lifshitz-Gilbert (LLG) equation, the magnetic structure of the 180° wall is expected to be a large vortex accompanied by a magnetic ripple structure. This complicated 180° wall is formed to suppress the demagnetizing energy due to a head-on-head configuration of the magnetization, which results in a micron-scale-wide transition area of the wall. The wire-width dependence of the 180° wall width obtained by micromagnetic calculation is almost consistent with that measured from the magnetic force micrograph.

著者

木村 崇 生嶋 君弥 若家 冨士男 蒲生 健次

出版者

公益社団法人 日本磁気学会

雑誌

日本応用磁気学会誌 (ISSN:02850192)

巻号頁・発行日

vol.25, no.4_2, pp.695-698, 2001 (Released:2007-02-02)

参考文献数

5

---

Hall resistance (HR) of a cross-shaped NiFe wire of submicron scale was investigated experimentally and numerically. We found that the HR curve showed various properties depending on the direction of the magnetic field and that the HR had three jumps corresponding to the switching fields in each probe. In order to control the magnetic fields where the HR shows the jumps, the effect of the pad pattern connecting to the wire on the switching field was investigated. The minor loop of the HR was also studied.

著者

山本 達治

出版者

公益社団法人 日本磁気学会

雑誌

日本応用磁気学会誌 (ISSN:02850192)

巻号頁・発行日

vol.3, no.3, pp.71-74, 1979-08-31 (Released:2010-05-18)

著者

富田 宏 宮島 英紀 近角 聡信 竹屋 浩幸 武居 文彦

出版者

公益社団法人 日本磁気学会

雑誌

日本応用磁気学会誌 (ISSN:02850192)

巻号頁・発行日

vol.13, no.2, pp.469-472, 1989-04-30 (Released:2007-12-07)

参考文献数

6

被引用文献数

2 2

---

The magnetic flux pinning in a superconducting Y1Ba2Cu3Oy single crystal and polycrystal has been investigated in magnetic fields up to 8 kOe using torque magnetometry. The magnetic torque curve shows an anisotropic rotational hysteresis loss. The results are interpreted in terms of anisotropic flux pinning and creeping effect.

著者

稲葉 信幸 宮島 英紀 武富 荒 近角 聡信

出版者

公益社団法人 日本磁気学会

雑誌

日本応用磁気学会誌 (ISSN:02850192)

巻号頁・発行日

vol.13, no.2, pp.245-248, 1989-04-30 (Released:2007-12-07)

参考文献数

4

被引用文献数

2 2

---

Magnetization (M), field induced magnetic anisotropy (Ku), rotational hysteresis loss (Erot) and melting point (Tm)f water- and paraffin-base ferrofluids were investigated in a temperature range from 77 K to 300 K as a function of the density of colloidal particles. Both paraffin and paraffin-base fluids were melted down at the temperature range from 180 to 210 K. In this range, the values of M and Erot, for paraffin-base fluids increased and Ku decreased with increasing temperature. These properties are interpreted by assuming that liquid-state and solid-state parts in paraffin exist in this tempetarure range and that the volume of solid-state part decreases with increasing temperature. The freezing point depression was observed in water-base fluids.

著者

稲葉 信幸 宮島 英紀 武富 荒 近角 聡信

出版者

公益社団法人 日本磁気学会

雑誌

日本応用磁気学会誌 (ISSN:02850192)

巻号頁・発行日

vol.12, no.2, pp.283-286, 1988-04-30 (Released:2007-12-07)

参考文献数

6

被引用文献数

5 3

---

The magnetization process of a ferrofluid whose carrier fluid is paraffin was investigated in a temperature range from 77K to 300K as a function of the intensity of cooling field and the freezing rate. Phase transition between liquid state and solid state can be simulated by using the ferrofluids as a magnetic probe. The uniaxial magnetic anisotropy was induced by field cooling in frozen ferrofluids. This induced anisotropy decreased with increasing temperature near the melting point and disappeared at 30K higher temperature than the melting point. In this region the rotational hysteresis was observed. The anisotropy constant K near the melting point was described by the equation K=A·exp(ΔEK/kT). The value of the activation energy ΔEK was almost the same as that of ΔEη estimated from the viscosity vs. temperature relation η∝ exp(ΔEη/kT).

著者

武富 荒 小川 伸一 宮島 英紀 近角 聡信

出版者

公益社団法人 日本磁気学会

雑誌

日本応用磁気学会誌 (ISSN:02850192)

巻号頁・発行日

vol.12, no.2, pp.263-268, 1988-04-30 (Released:2007-12-07)

参考文献数

20

被引用文献数

14 16

---

Magnetooptical effect of magnetic fluids is investigated. The phase difference θ between the ordinary ray and the extraordinary ray which are transmitted through the magnetic fluid thin film was found to be described in the functional form θ1f(H)/[T-T1+f(H)], where H is the magnetic field applied to the magnetic fluid thin film, T is the absolute temperature of the film, f(H) is a certain increasing function of H and T1, θ1 are the positive constants. The field dependence of light transmissivity of magnetic fluid thin films is well described by the cluster model of ferrous colloidal particles in the applied field direction when the aggregation is small. The field dependence of transmissivity is, however, interpreted neither by the electric absorption of the clusters nor by the Rayleigh scattering when the cluster becomes larger. The diffraction effect by the linear clusters directed to the applied field must be taken into account in interpreting the light extinction.

著者

茅 誠司

出版者

公益社団法人 日本磁気学会

雑誌

日本応用磁気学会誌 (ISSN:02850192)

巻号頁・発行日

vol.1, no.3, pp.1-4, 1977-11-30 (Released:2010-05-18)

著者

宮原 将平

出版者

公益社団法人 日本磁気学会

雑誌

日本応用磁気学会誌 (ISSN:02850192)

巻号頁・発行日

vol.2, no.2, pp.29-32, 1978-05-31 (Released:2010-05-18)

著者

浅沼 満

出版者

The Magnetics Society of Japan

雑誌

日本応用磁気学会誌 (ISSN:02850192)

巻号頁・発行日

vol.5, no.1, pp.1-5, 1981-02-28 (Released:2010-05-18)

著者

外村 彰

出版者

The Magnetics Society of Japan

雑誌

日本応用磁気学会誌 (ISSN:02850192)

巻号頁・発行日

vol.5, no.1, pp.6-11, 1981-02-28 (Released:2010-05-18)

参考文献数

28

被引用文献数

1 1

---

Electron holography has recently made a remarkable progress due to the high coherence of an electron beam generated in a field emission electron microscope and almost reached the stage of practical reality.Holographic interference electron microscopy was realized which gives information on magnetization distribution of specimen. Interference fringes in a contour map were proved to be along the in-plane magnetic lines of force when the thickness was uniform and the magnetic field was closed in the specimen.

著者

近角 聰信

出版者

公益社団法人 日本磁気学会

雑誌

日本応用磁気学会誌 (ISSN:02850192)

巻号頁・発行日

vol.3, no.2, pp.39, 1979-05-31 (Released:2010-05-18)

著者

藤田 浩一 張 濤 井上 明久 牧野 彰宏

出版者

公益社団法人 日本磁気学会

雑誌

日本応用磁気学会誌 (ISSN:02850192)

巻号頁・発行日

vol.22, no.4_2, pp.381-384, 1998 (Released:2007-06-29)

参考文献数

8

---

New Fe-based amorphous alloys exhibiting the glass transition and supercooled liquid region before crystallization were searched for in the composition range of Fe63Co7Nd10-xZrxB20 (x=0 to 6 at%). Amorphous alloys containing 4 to 6 at%Zr were found to exhibit the glass transition followed by a supercooled liquid region. The crystallization of the 4 at%Zr and 6 at%Zr alloys occurred in three stages. In the crystallized state, the alloys exhibited hard magnetic properties, namely, Js of 1.15 to 1.18 T, Jr of 0.75 to 0.76 T, and Nd2Fe14B phases for the 4 at%Zr alloy subjected to optimum annealing were about 50 nm and 30 nm, respectively, and the exchange magnetic coupling interaction between the α-Fe and Nd2Fe14B phases is thought to make possible the appearance of the hard magnetic properties.

著者

山崎 慶太 奥田 清明 阿部 隆之 内川 義則 志村 徹 小谷 誠

出版者

公益社団法人 日本磁気学会

雑誌

日本応用磁気学会誌 (ISSN:02850192)

巻号頁・発行日

vol.16, no.6, pp.769-774, 1992-12-01 (Released:2013-01-11)

参考文献数

7

被引用文献数

6 7

---

This paper describes the design and the development of a prefabricated magnetically-shielded-room (PMSR) of the hexagonal type for high sensitive measurement of neuro-magnetic fields such as magnetoencephalography (MEG) mainly using SQUIDs with first and/or second-order gradiometers. This PMSR consists of prefabricated plywood panels 1.2 m wide×2.4 m high×24 mm thick. It covers a floor area of about 9 m2. The panel is sandwiched by two layers of high-μ metal sheets 1 mm thick. The shielding factor at the center of PMSR against the external magnetic field is 20 to 40 dB in the range of DC to 120 Hz. Magnetic noise inside PMSR measured by a second-order gradiometer was less than hundreds fT above 0.5 Hz excepting 50 Hz. In this case, a second order gradiometer was able to eliminate the common mode magnetic noise of about 20 Hz, which was essentially observed by a magnetometer, caused by the vibration of PMSR. These results were discussed and compared with the calculations.

著者

能登路 淳 菊川 亮一 藤井 直樹 早川 元造 斉藤 皓彦

出版者

The Magnetics Society of Japan

雑誌

日本応用磁気学会誌 (ISSN:02850192)

巻号頁・発行日

vol.22, no.4, pp.657-660, 1998-04-15

参考文献数

6

被引用文献数

2 2

---

The effects of tensile stress and strain on magnetization and magnetic domains in grain-oriented silicon steel sheets were investigated. The strain-magnetization properties of plastic deformation regions under stress showed peculiar characteristics. The magnetization increased with decreasing strain and, after reaching a peak value, decreased with decreasing strain. We observed Lancet domains in a sample after removing stress applied to a plastic deformation region. This phenomenon can be explained by changes in the domain structures, which were partly observed. The results obtained in this investigation can be applied to the nondestructive detection of fatigue in metallic magnetic materials.

著者

木原 隆幸 小野 寛太 奥田 太一 原沢 あゆみ 尾嶋 正治 横尾 篤 木下 豊彦

出版者

公益社団法人 日本磁気学会

雑誌

日本応用磁気学会誌 (ISSN:02850192)

巻号頁・発行日

vol.25, no.4_2, pp.1059-1062, 2001 (Released:2007-02-02)

参考文献数

11

被引用文献数

2 3

---

The magnetic properties of thin films with reduced lateral dimension are significantly different from those of materials in the bulk state, and have provided a wealth of scientific interest and potential technological applications. It is therefore very important to study magnetism in microstructures or small magnetic domains, and one of the most powerful tools for investigating such magnetism is the photoelectron emission microscope with synchrotron radiation as its light source (SR-PEEM).We report in this paper our set-up of a new SR-PEEM system, and present the preliminary results.

著者

千田 正勝 武井 弘次 石井 修 越本 泰弘 戸島 知之

出版者

公益社団法人 日本磁気学会

雑誌

日本応用磁気学会誌 (ISSN:02850192)

巻号頁・発行日

vol.19, no.2, pp.465-468, 1995-04-01 (Released:2007-11-07)

参考文献数

13

被引用文献数

4 4

---

This study reports on the performance of a thin-film magnetic sensor that uses impedance change at a high frequency. A closed magnetic circuit, a strip pattern for the magnetic films, and an NiFe/SiO2 multilayer film structure were adopted for high sensitivity and large voltage change. A voltage change ratio of 50-60% was achieved by applying an external field of several Oe with an AC carrier of ∼800 MHz. The sensor was confirmed to perceive a highfrequency external field as an amplitude modulation of the AC carrier voltage, and exhibited broad frequency bandwidth, high linearity, and no hysteresis or Barkhausen noise.

著者

小澤 哲也 馬渡 宏 薮上 信 石山 和志 荒井 賢一

出版者

公益社団法人 日本磁気学会

雑誌

日本応用磁気学会誌 (ISSN:02850192)

巻号頁・発行日

vol.29, no.8, pp.831-837, 2005 (Released:2007-05-10)

参考文献数

5

被引用文献数

2 2

---

The impedance and phase characteristic of a magnetic thin film changes when a magnetic field is applied. The high-frequency-carrier magnetic field sensor, also called a GMI sensor, employs this phenomenon as its principle. We directed our attention to the change in the phase characteristic, and measured the dc magnetic field by measuring the phase as a phase difference, using the dual-mixer time-difference method. We optimized the method and the continuous sampling condition to measure the phase difference, and developed an efficient system for measuring the continuous sampling phase difference with low noise. The system was successfully used to measure the ac magnetic field by continuous sampling of the phase difference of a high-frequency-carrier magnetic field sensor.

著者

Giles Roscoe C. Mansuripur Masud

出版者

社団法人 日本磁気学会

雑誌

日本応用磁気学会誌 (ISSN:02850192)

巻号頁・発行日

vol.17, no.1, pp.S1_255-257, 1993

被引用文献数

1

---

Computer simulations of a two-dimensional lattice of magnetic dipoles are performed on the massively parallel Connection Machine Supercomputer. These lattices constitute a discrete model for thin films of amorphous rare earth-transition metal (RE-TM) alloys, used in erasable optical data storage systems. The simulated dipoles follow the dynamic equation of Landau-Lifshitz-Gilbert. Using mean-field theory, we have calculated the temperature dependence of the subnetwork magnetizations, the effective fields, the gyromagnetic coefficient, and the Gilbert damping parameter. These results are then used in the simulation of the thermomagnetic recording process, where a focused laser beam creates a hot spot and allows an external magnetic field to reverse the direction of local magnetization. Reversed domains are seen to nucleate during cooling of a heated spot with Gaussian spatial profile. In the absence of defects of the size of a domain wall, these nuclei are seen to collapse in low external fields. In contrast, samples with patches of uniform anisotropy and weakened inter-patch exchange form stable reversed domains. Color visualizations of the magnetization distribution show local pinning of the cooling reverse domain on patch boundaries.

著者

片根 保

出版者

公益社団法人 日本磁気学会

雑誌

日本応用磁気学会誌 (ISSN:02850192)

巻号頁・発行日

vol.22, no.4_2, pp.789-791, 1998 (Released:2007-06-29)

参考文献数

12

---

The effects of dc magnetic fields on animals and plants have been studied for a long time. In particular, many studies of the effects on plants have been reported, because of the ease with which experiments can be controlled. However, it is still not clear whether dc magnetic fields have any influence on plants. This study shows the effects of both horizontal and vertical dc magnetic fields on the growth of Japanese radishes. A dc magnetic field plays a role in restricting the initial growth of radishes, and the growth and root hair are also affected by the direction of the magnetic field.