1989 Fiscal Year Final Research Report Summary
DEPENDENCE OF SOLUTE DIFFUSION ON SOLUTE MAGNETIC MOMENT IN FERROMAGNETIC METALS
| Project/Area Number |
63550468
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Physical properties of metals
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
IIJIMA Yoshiaki TOHOKU UNIVERSITY, FACULTY OF ENGINEERING, RESEARCH ASSOCIATE, 工学部, 助手 (70005411)
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| Project Period (FY) |
1988 – 1989
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| Keywords | Diffusion / Magnetic transformation / Solute diffusion / Impurity diffusion / Solute atomic magnetic moment / Substitutional diffusion / Interstitial diffusion / Curved Arrhenius plot. |
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| Research Abstract |
The aim of this study is to elucidate a relationship between the influence of the magnetic transformation on solute volume diffusion and the magnetic moment of the diffusing atoms on the basis of precise measurements of volume diffusion coefficients of various solute atoms in the ferromagnetic Fe and Co. volume diffusion coefficients of substitutional solutes, ^<59>Fe, ^<57>Co, ^<51>Cr and ^<63>Ni in Fe and ^<57>Co in Co have been determined by the radio-frequency serial-microsectioning method which enables us to measure diffusion coefficients as small as 10^<-23> m^2s^<-1>. The Arrhenius plot of these volume diffusion coefficients shows linearity in the paramagnetic state, however, in the case of Co in Fe the curved Arrhenius plot is shown even above the Curie temperature. The influence of the magnetic transformation on the diffusion of Co in Fe is the largest and that of Cr in Fe is the smallest. This relation is consistent with the positive large magnetic moment of Co and with the negative large magnetic moment of Cr in Fe. Diffusion coefficient of C in Co has been determined by the residual activity method. Literature data on the diffusion of C and N in Fe have been examined. The influence of the magnetic transformation on the diffusion of interstitial atoms in ferromagnetic Co and Fe has been confirmed. The extent of it can be represented by the same equation as that in the case of the substitutional diffusion. The influence of the magnetic transformation on the diffusion of C in Co and that of C and N in Fe has been found to be larger than those in the self-diffusion in Co and Fe, respectively.
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