TITLE: A New Interatomic Potential for Cu-Ni Alloys and Its Applications: Growth of Cu-Ni Nanostructures on Cu(111)
Speaker: Dr. Berk Onat (Sabanci University)
Date/Time: February 19, 2014 Wednesday @ 14:40
Place: Sabanci University, SUNUM Seminar Room
A New Interatomic Potential for Cu-Ni Alloys and Its Applications: Growth of Cu-Ni Nanostructures on Cu(111)
We have developed a new semi-empirical and many-body type model potential to investigate static and dynamic properties of Cu-Ni alloys. The formalism is based on the embedded atom method with improved optimization techniques. To test the potentials, we calculated phonon dispersions of bulk Ni, Cu and its alloys and found that the results are consistent with the outcome of the experiments. In addition, we investigated the temperature dependent vibrational thermodynamical properties of Cu-Ni alloys with both disorder and order phases in fcc structures to further test the potential transferability to high temperature applications. Furthermore, we have studied energetics and growth mechanisms on nanostructures both using molecular dynamic simulations and total energy calculations to understand the nature of Ni and Cu growth on Cu(111) surface. Our simulations on Cu-Ni systems with mono/double-layer Ni islands on Cu(111) show that Cu atoms could migrate to Ni islands and decorate the bottom and even the upper layers of Ni islands. From total energy calculations we also discuss the governing diffusion mechanisms for the formation of Cu-Ni islands on Cu(111).