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Volume 22, Issue 9
Displaying 1-5 of 5 articles from this issue
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Contributed Paper
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I. Takekuma, M. Yasui, Y. Okumura, M. Akita, K. Sueoka, M. Haseyama, K ...1998 Volume 22 Issue 9 Pages 1251-1256
Published: 1998
Released on J-STAGE: June 29, 2007
JOURNAL OPEN ACCESSMagnetic force microscopy (MFM) is widely used to directly observe magnetized states with sub-micron resolution. The average profile, which is commonly used in the conventional quantitative analysis of MFM images, does not contain enough information to evaluate recording media. We introduce the concept of a stochastic process into MFM image analysis. By acquiring the statistical parameters-the average, the variance, and the histogram of the image-we reveal that the distribution of the fluctuation in the magnetic transition region is different from the Gaussian distribution. We also suggest a new evaluation value, L/W, which is related to the S/N of the read-back signal. With our model, it may be possible to obtain higher-order statistical parameters, which are important for achieving more precise characterization in the magnetic transition region.View full abstractDownload PDF (499K) -
M. Ikeda, I. Sasaki, K. Uemura, K. Mohri1998 Volume 22 Issue 9 Pages 1257-1261
Published: 1998
Released on J-STAGE: June 29, 2007
JOURNAL OPEN ACCESSThe sputtering technique was used to prepare 81-100 wt% Ni-Fe magnetostrictive films with compressive internal stresses on a SUS304 stainless steel shaft with large thermal expansion coefficient. The factors affecting the output characteristics of torque sensors are studied as functions of the shape of the sputtering pattern and the compositions and internal stresses of the Ni-Fe films. The sensitivity of a torque sensor is proportional to the film thickness. The optimal value of the Ni content of Ni-Fe films was found theoretically and experimentally in order to realize maximum sensitivity in torque sensing. Further, the effect of stress-relief annealing on the sensitivity of the torque sensors is discussed in conjunction with the internal stress of Ni-Fe films.View full abstractDownload PDF (351K) -
S. Soeya1998 Volume 22 Issue 9 Pages 1262-1267
Published: 1998
Released on J-STAGE: June 29, 2007
JOURNAL OPEN ACCESSExchange coupling of bcc-Fe55Co30Ni15/bcc-like-Cr45-Mn45Pt10 films and lattice distortion of their CrMnPt films were investigated. In this system, the unidirectional anisotropy constant (Ke) continued to increase even if the CrMnPt thickness (tCrMnPt) was more than the critical thickness, because the lattice distortion of the CrMnPt film was amplified by increasing tCrMnPt. The reason for this was that the total stress applied to the lattice of the CrMnPt film through annealing, due to a positive spontaneous lattice distortion of the CrMnPt film and a negative FeCoNi/CrMnPt lattice mismatch, increased with the depth in the CrMnPt layer from the interface. The Ke did not saturate at the critical thickness because of the negative FeCoNi/CrMnPt lattice mismatch.View full abstractDownload PDF (456K) -
N. Fukumuro, M. Konno, M. Chikazawa, T. Watanabe1998 Volume 22 Issue 9 Pages 1268-1272
Published: 1998
Released on J-STAGE: June 29, 2007
JOURNAL OPEN ACCESSThe relationship between the microstructure and magnetic properties of electrodeposited Fe-Ni binary alloy thin films throughout the composition range was investigated. In such films an α (bcc) phase existed up to 15at%Ni, a γ (fcc) phase existed beyond 35 at%Ni, and a mixed phase of α and γ existed from 15 to 35 at%Ni. The grain size of a film depended on the alloy composition without potential and the current density. The grain size of the α phase increased with the Fe content, while the grain size of the γ phase increased with the Ni content; therefore, the grain size of the mixed phase was the finest (< 10 nm) in all the obtained films. The saturated magnetization was proportional to the alloy composition. Dependence of the coercivity on the thickness and coercivity of thinner films (< 500nm) was strongly affected by the grain size.View full abstractDownload PDF (465K) -
K. Niizuma, K. Nagayama, Y. Utsushikawa1998 Volume 22 Issue 9 Pages 1273-1276
Published: 1998
Released on J-STAGE: June 29, 2007
JOURNAL OPEN ACCESSWe investigated the saturation magnetization and structure of iron foils treated by nitrogen plasma irradiation. The surface of each nitrided foil was removed step by step by electropolishing, and the saturation magnetization of the nitrided foil was then measured. X-ray diffraction patterns were taken from the electropolished surface at each step. Various iron nitrides were formed at all depths of foils nitrided for 5 hours or more, and their quantity increased with the nitriding time. The outermost region of the surface layer irradiated with nitrogen plasma was composed of γ'-Fe4N and ε-Fe3N, and the inner region was composed of α'-martensite. The saturation magnetization of α'-martensite in a foil nitrided for 13 hours was 223 emu/g. The nitrogen concentration of α'-martensite in the foil irradiated with nitrogen plasma was 0.5 atomic percent.View full abstractDownload PDF (325K)
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