Biomedical subjects

Grazyna Antczak

Publications and source records attributed to Grazyna Antczak.

2 recordsLinked to original sources

PubMed2004

Long jumps in surface diffusion.

Diffusion on metal surfaces is often viewed as the movement of atoms jumping between nearest-neighbor sites. However, statistical predictions suggest that at elevated temperatures longer jumps should become important. Now, with instruments such as the field ion microscope and the scanning tunneling microscope, which reveal individual adsorbed atoms, it has become possible to examine diffusion in some detail. Here we summarize the experimental efforts that have revealed the contributions of long jumps in various diffusion processes.

Journal Article↗

PubMed2004

Long jump rates in surface diffusion: W on W(110).

We have reexamined the diffusion of W adatoms on W(110) using the field ion microscope. The diffusivity is in good agreement with previous results and reveals no unusual features, but from observations of the distribution of displacements, corrected for diffusion during temperature transients, we have for the first time been able to measure the temperature dependence of rates for nearest-neighbor and double jumps, as well as for vertical and horizontal transitions. Activation energies and frequency factors for all the long jumps are significantly larger than for single jumps, and a simple model is proposed to account for our observations.

Journal Article↗