Comparison of Sn, Sb and Ge grain boundary diffusion in Cu

The main goal of this work is to compare data for grain boundary diffusion (GBD) Sn, Sb and Ge in Cu.

It is supposed to discuss the correlation between GBD parameters, solute melting temperature, ability to form the chemical compounds and solubility.

For all above mentioned systems the existence of many chemical compounds, both formed during initial crystallization as well as due to peritectic reactions, is typical.

Such peculiarity is usually favorable for the atomic complexes formation in grain boundaries (GB).

All these systems have sufficiently large solute solubility (up to 7,7at.% in Cu-Sn, 5,8at.% in Cu-Sb, and 12at.% in Cu-Ge) what leads to the low enrichment (segregation) coefficients (from 2 to 17 according to AES and EPMA data).

The essential difference consists in solute melting temperature: 232 C for Sn, 630 C for Sb, 938 C for Ge comparing with 1083 C for Cu.

There are bulk diffusion data for all systems and GBD data for diffusion Sb and Ge in Cu.It is important to note that the ratio of GBD activation energy (Egb) to the bulk diffusion activation energy (E) is approximately equal for Sb and Ge due to similarity of many chemical compounds and solubility.

For the full analysis the data on GBD Sn in Cu will be obtained.