[en] Low-temperature transport properties in a ferromagnetic Fe₁₉Ni₈₁ nanoring were studied. In the nanoring, resistance oscillation due to the Aharonov-Bohm effect of a conduction electron was observed. However, the reproducibility of resistance with magnetic field, which is usually observed in non-magnetic metals, was not observed. This result suggests that some kinds of degrees of freedom, which persist even at low temperature break in part the reproducibility of the aperiodic fluctuation in magnetoresistance

[en] The applied-voltage(V) dependence of current(I) passing ferromagnetic Ni quantum wires was investigated with holding a conductance-quantized state. Observed I-V exhibits three-types behaviors: I/V is almost identical up to 50 mV, or increases or decreases with V. The result suggests current-induced reconfiguration of magnetic structures around the quantum wires

[en] Field dependence of magnetization and magnetic torque in Fe/Cr multilayers were investigated. Magnetic torque measurement allows us to estimate directly the interlayer exchange coupling in the multilayers. The magnetization process depends critically on the number of the layers due to the magnetic-moment flop in the surface Fe layer

[en] The scanning Hall probe microscope (SHPM) which can be used in magnetic fields up to 15 kOe has been developed. A surface magnetic image in the ferromagnetic SmCo₅ film was measured under magnetic fields perpendicular to the sample with the SHPM. The observed images describe domain transitions consistent with the magnetization curve

[en] Galvanomagnetic effect of NiFe rings has been studied. It was found that the ring takes two kinds of magnetization state, closure domain state and bi-domain state. At very low temperatures, resistance oscillation and fluctuation were observed, indicating the existence of the quantum interference effects such as Aharanov-Bohm effect

[en] Magnetic properties of ferromagnet-superconductor hybrid films were investigated below and above the superconducting critical temperature. Below the superconducting critical temperature, the hybrid films show not only large coercive force but also hysteresis shift. These changes depend on the magnetic state in the ferromagnetic layer at the superconducting critical temperature. Magnetization process of ferromagnet-superconductor hybrid films is discussed in terms of the critical state model for flux pinning in the superconducting layer

[en] A method for detecting the helicity of magnetic-moment distribution in vortex states in a ferromagnetic mesoscopic ring has been developed. This method involves measuring an asymmetric component of the resistivity distribution as a function of the external field. This field-induced asymmetry reflects the direction of the magnetic-moment circulation via the anisotropic magnetoresistance effect, which allows precise measurements of magnetic structures

[en] The magnetic properties of a Ni₈₁Fe₁₉ honeycomb nano-network have been investigated by magneto-resistance measurements and magnetic-force microscopy. The results indicate that the magnetic properties of remanent state and the magnetic process in the network is governed strongly by magnetic interactions at the vertexes

[en] The magnetoresistance in an FeNi submicron-structure comprising two wires of 80 and 200 nm in width connected in series was measured at 77 K. When the external magnetic field was applied parallel to the wire axis, two switching fields corresponding to the distinct coercive force of the two wires were observed. When the external magnetic field was applied at an angle of θ>30 deg. to the wire axis one switching field was observed, indicating simultaneous magnetization reversal in both wires. This indicates that the domain-wall trapping around the joint can be controlled systematically in terms of the direction of the external magnetic field

[en] Development of an effective, high-power, low-cost, artificial light source for use in plant-growing facilities would be very beneficial for plant production. Recently, the laser-diode lamp was proposed as a new type of light source for plant production. The advantages of the laser-diode lamp over conventional light sources are its high electrical-to-optical power conversion efficiency, low thermal radiation, easy set-up for high power and pulse irradiation, small weight and small volume for mounting, and selectivity for proper wavelength. Because laser light itself differs from the light sources presently used in plant growing, we confirmed the possibility of growing plants under the laser-diode light using lettuces. Lettuce seedlings with 5-6 leaves were grown under a laser-diode lamp panel with 30 pieces of high-power and high-efficiency AlGaInP laser-diodes. The power of each laser-diode lamp was 500 mW, and the wavelength was 680 nm, which was efficient for photosynthesis. The lettuce plants were able to grow under the laser-diode light. However, plants were lighter and had thinner leaves than those grown under high-pressure sodium lamps. (author)