The diffusion coefficient DFe* of Fe in Au under a H 2 pressure of 5GPa has been determined in the temperature range from 1004 to 1301K by relating the interdiffusion coefficients in single-phase Au-(Au-Fe) couples with the Darken-Manning relation. The value of D Fe*, in Au at 130IK under a H22 pressure of 5 GPa is three times that under a pressure of 5 GPa without H2, whereas the former is one tenth of that under a He pressure of 0.1 MPa. The temperature dependence of DFe* in Au under a H2 pressure of 5 GPa can be expressed as DFe* = 7.8-5.6 +20 × 10-6 exp(-195 ± 12 kJ mol -1/RT) m2 s-1. The pre-exponential factor is nearly equal to that in He at 0.1 MPa, although the activation energy is only 21 kJ mol-1 larger than that observed in He at 0.1 MPa. This behaviour contrasts with that in γ-Fe, which has a very high solubility of H2 under high pressures.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics