| Autor: |
Lohmann, M., Divinski, S., Herzig, Chr. |
| Zdroj: |
International Journal of Materials Research: Zeitschrift fuer Metallkunde; February 2022, Vol. 94 Issue: 11 p1172-1178, 7p |
| Abstrakt: |
Grain boundary (GB) solute diffusion of Ge in Cu polycrystals was systematically investigated by the radiotracer serial sectioning technique using 68Ge and 71Ge isotopes. The diffusion measurements were carried out under conditions of Harrison’s B- (923–626 K) and C- (576–451 K) type diffusion regimes. In the B-type diffusion regime, the triple product P= sδDgb(sis the segregation factor and δthe GB width) was found to follow the Arrhenius law P= 4:0 × 10-16× exp(-58.6 kJ mol-1/RTÞ m3s-1, where Ris the universal gas constant and Tthe temperature. Measurements in the C-regime directly yielded the GB diffusion coefficient Dgb, Dgb= 2.8 × 10-6× exp(-84.8 kJ mol-1/RTÞ m2s-1. Combining the obtained Pand Dgbvalues and assuming δ≌ 5 × 10-10m, the GB segregation factor for Ge in Cu was determined to follow an Arrhenius dependence s= 0.29 exp(26 kJmol-1/RTÞ. The determined segregation coefficients sare discussed together with previous results on solute segregation in Cu and Ag, and it is concluded that the well-known Hondros relation, which relates segregation and bulk solute solubility, can generally be used only for a qualitative estimation of the segregation ability. Furthermore, the obtained results for the triple product sδDgband the directly measured Dgbvalues are discussed in relation to previous GB diffusion measurements of some other solutes in Cu and Ag in the B- and C-regimes. |
| Databáze: |
Supplemental Index |
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