Regensburg 2004 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
M: Metallphysik
M 8: Phasenumwandlungen I
M 8.4: Talk
Monday, March 8, 2004, 15:30–15:45, H4
Nucleation processes in Au-Ni alloys — •H. Reichert, A. Schöps, I. Ramsteiner und H. Dosch — MPI für Metallforschung, Heisenbergstr. 3, D-70569 Stuttgart
Au-Ni alloys exhibit a pronounced competition between ordering and phase separation. In the ground state the system is phase separated. We have investigated the early stages of phase separation in Au-Ni alloys after quenching alloy single crystals from the disordered high temperature phase into the miscibility gap. Time-resolved measurements of the diffuse scattering of Au3Ni2 alloy single crystals demonstrate the existence of two distinct nucleation channels in the precipitation of Au-rich particles from the host matrix. We find a fast nucleation channel which is producing extremely well-aligned Au precipitates in the host matrix. From the scattering data we can deduce a direct influence of the electronic structure of the host matrix onto the phase separation process