Foils of the γ-FeN phase were prepared by the conventional gas nitrification method in an NH₃ + H₂ atmosphere. We found the γ-FeN phase field extends beyond 11.1 at%N at 660°C, which is the stoichiometric composition of Fe₁₆N₂. The γ-FeN phase with 9.8 at%N is transformed into a mixture of the α' and γ phases by cooling to below 180 K. An intense external magnetic field at 4.2 K is found to drive the martensitic transformation occurring in the γ phase, and a field of 170 kOe reduces the amount of residual γ phase from 38% to 16%. This results in a drastic increase in the spontaneous magnetization from 147 emu/g to 198 emu/g.

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The sputtering technique was used to prepare Ni-Fe magnetostrictive films on Ti-alloy shafts. The factors affecting the output characteristics of the torque sensors are studied as functions of the circuit parameters, the shapes of patterns, and the compositions of Ni-Fe films. The sensitivity of a torque sensor is proportional to the frequency of the circuit, the pattern width, and the film thickness. The optimal value of the Ni content in Ni-Fe films was found theoretically and experimentally in order to realize maximum sensitivity in torque sensing.

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This paper describes the orientation of demembranated and nuclear-decondensed cattle sperm treated with 1% glutaraldehyde in a 5400-G static magnetic field. The sperm collected from four bulls was mixed with the same sperm density. One-percent triton X-100 was used to extract the sperm plasma membrane, while 10 mM dithiothreitol and heparin sodium were used to decondense the sperm nucleus. The intact, demembranated, and nuclear-decondensed sperm non-treated or treated with glutaraldehyde were exposed continuously for 24 hours to a 5400-G magnetic field at 25°C. The demembranation and treatment with glutaraldehyde enhanced the orientation of the sperm. However, nuclear-decondensed sperm, as well as non-exposed sperm, had a very low perpendicularly oriented percentage, while the flagella showed low parallel orientation. These findings suggest that the magnetization of cattle sperm heads occurs in the chromatin.

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The compositional dependence of the glass-forming ability and magnetic properties of Fe-Al-Ga-P-C-B- (Si) glassy alloys was investigated. The saturation magnetization (σ_s) increase with increasing Fe content. While the maximum thickness for glass formation (t_max) decreases when the (P, C, B) is replaced by Fe, it hardly does so when the (Al, Ga) is replaced by Fe. When P is replaced by Si, t_max increases. As a result, a high σ_s of 207 × 10^-6 Wbm kg^-1 and a large t_max of 220 μm were simultaneously obtained in a Fe₇₇Al_2.14Ga_0.86P_8.4C₅B4Si_2.6 glassy alloy. The core loss of this glassy alloy with a smaple thickness of 100μm at f=50 Hz and B_m = 1.0 T was 0.22 Wkg, which is lower than those of 6.5%Si-Fe alloy and amorphous Fe₇₈Si₉B₁₃ alloy with the same sample thickness. Therefore, it can be said that the Fe-Al-Ga-P-C-B-Si glassy alloys are useful for inductive applications.

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he effects of Mn excess and deficiency on the magnetoresistive properties of La-Sr-Mn-O thin films were investigated. Epitaxial and textured films of La_0.72Sr_0.28Mn_yO_3-δ (y: 0.86-1.58) were prepared by rf sputtering on (100) SrTiO₃ and (110) sapphire single crystal substrates, respectively. The resistivity of the epitaxial films was less than 10% of that of the textured films, and the resistivity of all the films decreased with increasing Mn content. The Mn content and substrate material affected the temperature dependence of the magnetoresistance as well as the crystal quality of the films. The nonstoichiometry of manganese played a significant role in the electric and magnetic properties of La-Sr-Mn-O thin films.

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