Phys.org October 16, 2024
A team of researchers in the US (George Washington University, George Mason University, Lawrence Berkeley University, Johns Hopkinson University, Sandia National Laboratory, Leigh University) presented large-scale atomistic simulations that revealed triple junction (TJ) segregation in Pt–Au nanocrystalline alloys in agreement with experimental observations. While existing studies suggested grain boundary solute segregation as a route to thermally stabilize nanocrystalline materials with respect to grain coarsening, the researchers quantitatively showed that it was specifically the segregation to TJs that dominated the observed stability of the alloys. The results showed that doping the TJs made them immobile, thereby locking the grain boundary network and hindering its evolution. In dilute alloys the grain boundary and TJ segregation were not as effective in mitigating grain coarsening. According to the researchers their work highlights the need to account for TJ segregation effects to understand and predict the evolution of nanocrystalline alloys under extreme environments… read more. Open Access TECHNICAL ARTICLEÂ
Graphical abstract. Credit: Nano Letters, Vol 24/Issue 31, July 29, 2024