We report the carrier-doping effects in layered manganese oxysulfides Sr₂CuMnO₃S and Sr₄Cu₂Mn₃O_7.5S₂ with a two-dimensional SrMnO_x perovskite-like layer. According to the Cu 2p core-level x-ray photoemission spectroscopy (XPS), Cu ions of Sr₂CuMn_1-xZnO₃S and Sr_4-xLa_xCu₂Mn₃O_7.5S₂ are Cu¹⁺ and Cu¹⁺/Cu²⁺, respectively. On the other hand, the Mn 2p XPS spectra indicate that the Mn ions are Mn³⁺ in mother compounds (Sr₄Cu₂Mn₃O_7.5S₂ and Sr₂CuMnO₃S), and that they are Mn³⁺/Mn⁴⁺ in Sr₂CuMn_1-xZn_xO₃S. Sr₂CuMnO₃S exhibits low- dimensional antiferromagnetic ordering at 120K, while an increase tendency of magnetic susceptibility in cooling is observed below 50 K. The antiferromagnetic order of Sr₂CUMn_1-xZn_xO₃S (x ≤ 0.2) is destroyed by an increase in non-magnetic Zn²⁺ ions, and the steepness of the increase tendency of magnetic susceptibility in cooling is also enhanced by increasing Zn²⁺ ions. It is supposed that ferromagnetic and antiferromagnetic magnetic order co-exist in Sr₂CuMn_1-xZn_xO₃S. The La-doped samples Sr_4-xLa_xCu₂Mn₃O_7.5S₂ (x ≤ 0.2) show spin-glass-like behavior below 200 K. It is ascribed to the competition between the weak ferromagnetic double exchange interaction and the antiferromagnetic super-exchange interaction.

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In this study, the effect on collagen gel contractions induced by a mesenchymal cell, such as an osteoblast, under the high magnetic fields and the addition of bioceramics was investigated. The biological activities of collagen and bioceramics, such as hydroxyapatite, in relation to bone cells, such as osteoblasts, with and without a high magnetic field of 14 T were examined using observation of collagen gel contractions. The morphology of contracted collagen gel with whisker-like hydroxyapatite after 48 hours was ellipsoidal with the major axis parallel to the collagen orientation direction and perpendicular to the applied magnetic field of 14 T. On the other hand, the gels with whisker-like hydroxyapatite under a high magnetic field also showed a contraction after 74 hours, and the shape of the contracted gel was a perfect circle. The behavior of collagen gel contractions was applicable to the synthesis of biomaterials.

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Rotating permanent-magnets demagnetization is able to demagnetize a magnetized sample on the moving belt within comparatively short time. However, the operation principle of the demagnetization has not clarified yet. This paper discusses the mechanism of demagnetization and the relationship between structure of the demagnetizer and effect of demagnetization. The following points are obtained. (1) It is clarified experimentally that the mechanism of the demagnetization can be accounted for loop-attenuation demagnetization. A reasonable relationship between the demagnetizing frequency and the velocity of a sample is also proposed. (2) An empirical equation for demagnetization is shown analytically that three important parameters are closely related to the magnetized energies and the magnetic poles of the permanent-magnets.

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By using a ferrite plating technique and stereolithography, we fabricated the medical magnetic micro-machines that plated ferrites on a spiral-structured resinous substrate. We plated a magnetite (Fe₃O₄) film with good biocompatibility and Co_xFe_3-xO₄ films (CO_0.39Fe_2.61O₄ or Co_0.45Fe_2.55O₄) having large coercive force onto template bodies at 90°C for 5-8 hours, and fabricated solid-state-based ferrite-coated micro-machines with biocompatibility and light mass density. All the micro-machines were able to swim in water when an external rotational magnetic field was applied.

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Amorphous melt-spun ribbons of low rare-earth (Pr = 6 at.%) α-Fe/Pr₂Fe₁₄B-type Pr-Fe-Co-V-Nb-B system alloys were prepared by the single-roller liquid rapid-quenching method, and the effects of composition, substrate surface velocity, and annealing conditions on the magnetic properties were studied. The optimum preparation conditions and some of the properties were as follows: composition, Pr₆Fe₇₇Co₈V₁Nb₁B₇; substrate surface velocity, 40.0 m/s; annealing conditions, 575°C (heating rate: 575°C/min) for 5 min in Ar atmosphere; magnetic properties, (BH)_max = 120.2 kJ/m³ (15.1 MGOe), H_cJ = 360 kA/m (4.5 kOe), H_cB = 300 kA/m, J_r = 1.2 T, recoil ratio = 75%, H_k/H_cJ×100 = 25.3%, α(J_r) = −0.038%/°C, α(H_cJ) = −0.37%/°C, T_c = 420°C. The value of (BH)_max for a compression-molded Pr₆Fe₇₇Co₈V₁Nb₁B₇ isotropic bonded magnet prepared by using ribbons annealed at 575°C for 5 min was 56.0 kJ/m³ (7.0 MGOe) and the density was 5.70 Mg/m³.

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A hybrid thin-film coplanar transmission line with a magnetic/dielectric bilayer structure was fabricated. The hybrid coplanar transmission line device consisted of a top aluminum conductor layer, a dielectric layer (polyimide: 1μm), and a bottom magnetic layer (CoZrNb: 1μm) on the glass substrate. The top conductor layer consisted of a signal line and ground planes in the same plane. The device exhibited the same transmission characteristic as a magnetic (CoZrNb: 1μm)/dielectric (polyimide: 1μm) multilayer hybrid thin-film microstrip line. As a result, the coplanar line exhibited the same wavelength-shortening ratio and insertion loss per unit line length as the microstrip line.

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Melt-spun ribbons of Pr_xFe_91.5-x-y-zCo₈Ti_yB_zSi_0.5 (x = 9.0-11.0, y = 0.5-2.0, z = 7.5-11.5) alloys were prepared by the single roller liquid rapid-quenching method, and the effects of composition, substrate surface velocity and annealing condition on the magnetic properties were studied. The optimum preparation conditions and some of the properties were as follows: composition: Pr₁₀Fe_69.5Co₈Ti_1.5B_10.5Si_0.5; substrate surface velocity: 10.0 m/s; annealing condition 650°C for 0 min in Ar atmosphere; magnetic properties: (BH)_max = 119.9 kJ/m³, H_cJ = 1004.0 kA/m, H_cB = 559.3 kA/m, J_r = 0.87 T, recoil ratio = 29.0 %, H_k/H_cJ×100 = 33.0 %, α(J_r)_ave = −0.047 %/°C, α (H_cJ) = −0.43 %/°C and T_c = 393 °C. From TEM observation, the average particle size of this ribbon was found to be about 16 nm. Compression-molded isotropic bonded magnets were prepared by using Pr₁₀Fe_69.5Co₈Ti_1.5B_10.5Si_0.5 ribbons annealed at 650 °C for 0 min. Their magnetic properties were (BH)_max = 80.2 kJ/m³, H_cJ = 953.1 kA/m, H_cB = 461.9 kA/m, J_r = 0.69 T, H_k/H_cJ×100 = 32.8 %, irreversible loss = −2.12 % (at 125 °C), density = 6.29 Mg/m³.

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In recent years, several inverse solutions of magnetoencephalography (MEG) have been proposed. One of them, the multiple signal classification (MUSIC) method, utilizes spatiotemporal information obtained from magnetic fields. The conventional MUSIC method is, however, sensitive to Gaussian noise, and a sufficiently large signal-to-noise ratio (SNR) is required to estimate the number of sources and to specify the precise locations of electrical neural activities. In this paper, a universal fourth order MUSIC (UFO-MUSIC) method, which is based on fourth order statistics, is proposed. This method is shown to be more robust against Gaussian noise than the conventional MUSIC method. It is an algebraic approach to independent component analysis (ICA) . Although ICA and the analysis of the MEG inverse problem have been separately discussed, the proposed method incorporates ICA into the MEG inverse solution. The results of numerical simulations demonstrate the validity of the proposed method.

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