Activation Volumes of Interstitial Diffusion in Ferromagnetic Metals and Alloys
1971; American Physical Society; Volume: 3; Issue: 3 Linguagem: Inglês
10.1103/physrevb.3.815
ISSN0556-2805
AutoresManfred Wuttig, James R. Keiser,
Tópico(s)Microstructure and Mechanical Properties of Steels
ResumoThe disaccommodation technique was used to determine the activation volumes of carbon diffusion $\ensuremath{\Delta}V$ of a Fe-1.4 wt% Si alloy, of hcp cobalt, and of nickel at the temperatures of -21, 75, and 110\ifmmode^\circ\else\textdegree\fi{}C, respectively. The obtained values of $\ensuremath{\Delta}V$ are +0.3 \ifmmode\pm\else\textpm\fi{} 0.3 and -0.6 \ifmmode\pm\else\textpm\fi{} 0.9 ${\mathrm{cm}}^{3}$ ${\mathrm{mole}}^{\ensuremath{-}1}$ for the two relaxations observed in hcp cobalt, and 1.2 \ifmmode\pm\else\textpm\fi{} 0.1 ${\mathrm{cm}}^{3}$ ${\mathrm{mole}}^{\ensuremath{-}1}$ for nickel. These results are discussed in terms of a continuum model that interprets the activation energy of diffusion as a sum of the strain and exchange energies. It is found that in ferromagnetic solids the activation volume of diffusion is essentially controlled by the ferromagnetic anharmonicity.
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