We report on magnetoresistance measurements in a heavy metal/ Mn₃Ir multilayers. After a post annealing process, we observed the magnetoresistance associated with the ordered crystalline structure of the Mn₃Ir. The resistance change as a function of the strength as well as the direction of the applied field suggests that the magnetoresistance is partially related to a modification of the Néel order by the magnetic field. Our further detailed investigation revealed that there is an additional component of the resistance change, perhaps due to the non-collinear magnetic structure associated with the L1₂-ordered Mn₃Ir, which cannot be accounted for by any conventional magnetoresistance effects.

  High coercivity FePt•MgO films were successfully synthetized on cone-shape Si tips in a very high frequency (VHF) plasma irradiation-assisted magnetron sputtering system to prepare the MFM tips for evaluation of the AC magnetic field of perpendicular magnetic write head at high write current. Alloying with MgO significantly enhanced the coercivity of the magnetic coating due to the isolation of FePt grains by MgO. As a result, a high coercivity close to 20 kOe was achieved. The AC magnetic field images of the perpendicular magnetic write head at high write current were taken on alternating MFM (A-MFM) by this tip. A clear amplitude image with a strong signal at the main pole position was observe compared to the pure FePt layer-coated tip, which gave a blurry image and very small amplitude. Fourier analysis of the images obtained by this kind of FePt•MgO tip gives a spatial resolution of about 15 nm in air atmosphere. It is clear that the cone-shape FePt•MgO-coated MFM tip with a coercivity higher than the magnetic field to be measured is effective and capable for measuring the high AC magnetic field for an HD perpendicular magnetic write head at a very high write current.

  Grasping and conveying an object, by utilizing the frictional force generated by contact is performed in various processes in the manufacturing line for an industrial product. The deterioration of the surface quality due to these contacts is a problem. As a solution to this problem, a noncontact transport of steel plates, using electro-magnetic force, has been proposed. However, in these systems, electromagnets are installed vertically. In this method, if the steel plate is thin and does not have sufficient flexural rigidity, it is difficult to add a suspension force for levitation over the entire steel plate. In order to solve this problem, we proposed an edge supported electromagnetic levitation system for flexible steel plates using electromagnets installed horizontally. In order to verify the effectiveness of the proposed system we constructed a prototype of an edge-supported type magnetic levitation system, which applied electromagnetic force only from the horizontal direction of the steel plate. Consequently, we carried out levitation experiment and discussed characteristics of horizontal positioning and levitation suspension.