Study on Phase Transformations for New Materials and under Special Conditions

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The characteristics of phase transformations have been invsestigated for new materials such as amorphous alloys and zeolite clusters, and also under various specific circumstances. About 80% of initial project planes was done in successfully. The study was done for three subjects. Main results are as follows : (1) Experimental and theoretical appoaches for understanding of phase transformations under specific circumstances ; Dr.HONO studied initial stages of phase transformations in nano-composite types of soft magnetic materials in atomic scale, and demonstrtaed that some impurities such as copper and niobium play an important role for soft magnetic properties and proposed a new concept to fabricate new types of soft materials. Dr.TERASAKI examined crystal structures in various zeolites by a combination of X-ray diffraction and electron microscopy, and also demostrated a new concept to fabricate new types of materials by controlling micro-meso spacial structures. (2)Material propertie … More s in artificially fabricated materials such as multilayers and metastable phases ; Dr.MATSUI examined the magnetic properties of arificial multilayer films containing iron element, and proposed a new model to explain the phase stability of metastable fcc and bcc iron phases. Dr.NITTONO examined various metastable phases which are hard to be formed thermodymanically, and demostrated that various metastable phases and alloys are easily fabricated under plasma states by sputtering, and various types of phase transformations are applicable to the improvement of practical materials. (3)Analysis of non-crystal to crystal types of phase transformations in amorphous alooys and quaisi-crystals ; Dr.INO examined magnetic properties of amorphous alloys containing Sm element, and explained successfully the mechanism of magmetic transformation in terms of temperature. Dr.HIROTSU developped new types of analytical techniques for amorphous alloys by the combination of electron diffraction, radial distribution analysis and structursl simulation method, and applied to the analysis of microstructures in amorphous soft magnetic materials. Some of researchers also collaborated with each other to elucidate the mechanism of the initial stage of phase separation. A lot of new knowledges which are applicable and useful were also obtained from this study. Less