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Publications (3)3.89 Total impact

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    ABSTRACT: A high-speed polarizing microscope system combined with a 37 T pulse magnet has been developed. This system was applied to successfully visualize the field-induced collapse of charge-orbital ordering in a layered manganite La(1/2)Sr(3/2)MnO(4). Quantitative analyses of the obtained polarizing microscope images provided clear evidence of this transition in contrast to rather moderate changes in magnetization and magnetoresistance. The ability of this system to carry out quantitative analysis was further tested through the observation of Faraday rotation in a Tb(3)Ga(5)O(12) crystal. The Verdet constant determined from the polarizing images is in reasonable agreement with that in literature. Local intensity analyses of the images indicate that we can investigate magneto-optical signals within an accuracy of 0.85% in an area of 9.6 x 9.6 microm(2).
    The Review of scientific instruments 04/2010; 81(4):043701. · 1.52 Impact Factor
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    ABSTRACT: We developed a high-speed polarizing microscope imaging system combined with a 37 T pulse magnet. With utilizing this system, we can visualize some kinds of structural transitions induced by high magnetic fields. The efficiency of this system was tested through observation of the field-induced collapse of charge-orbital ordering (COO) in mixed-valent manganites. In perovskite-type Nd1/2Sr1/2MnO3, quantitative analyses of the obtained polarizing microscope images clearly show the discontinuous change in birefringence accompanied with hysteresis, which are characteristic of the first order transitions. This observation of field-induced melting of the COO was also successful in a layered manganite La1/2Sr3/2MnO4 in which changes in magnetization and magnetoresistance at the transition are less clear. The present success in observation of the melting of the COO demonstrates the potential applicability of this system to visualize other kind of structural transitions even in a tiny piece of crystal.
    Journal of Low Temperature Physics 04/2010; 159(1):319-323. · 1.18 Impact Factor
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    ABSTRACT: Recently, much progress has been made in generation of high magnetic fields in the International MegaGauss Science Laboratory at ISSP of the University of Tokyo. The electro-magnetic flux compression method has been improved to establish the world highest indoor-field of about 730 T. In addition to the destructive methods, a new project aiming at the non-destructive generation of both long pulsed- and 100 T-fields is progressing. The long pulse project is introduced. Not only for the highest field but also for various experiments, many kinds of coils have been developed. A microscope imaging system under pulsed fields, and miniature magnets for the X-ray measurements at the synchrotron radiation facility are also presented. High Field Lab-ISSP
    Journal of Low Temperature Physics 01/2010; 159(1):381-388. · 1.18 Impact Factor