| Below are terse descriptions of the past and current research I have undertaken at U. C. Berkeley. There are also links to pages describing the work in more detail and a list of my academic publications. |
| Studies are focused on using the strain field from a network of misfit dislocations in a substrate to act as a template for the growth of regular nano-structures. There are two main strategies to achieve this end. The first is to grow in hetrogenaities with the desires length scale during film deposition. To study this we are using Kinetic Monte Carlo simulations to understand how the strain topography influences segregation and nucleation in the early of island growth during hetroepitaxial deposition of a binary alloy. The second approach uses the dislocation strain field to trigger spinodal decomposition of an initially homogeneous binary film. The feasibility of this as a process is investigated with a continuum elasticity model of spinodal decomposition in a thin film. |
| Overview | Spinodal Decomposition | Island growth |
| A crystalline material will not act a a perfect oscillator but rather will dissipate vibrational energy internally. This so called "internal friction" arises from many mechanisms. One source of internal friction is dislocation motion. Studying the spectrum of vibrational energy dissipation offers a way of measuring some of the properties of dislocation dynamics. In order to interpreter these measurements however an understanding is needed of the mechanism by which energy is dissipated. |
| Internal Friction Overview | Summary of work |
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"Pt adatom diffusion on strained Pt(001)", Wei Xiao, P. Alex Greaney, and D. C. Chrzan, Physical Review B, Vol. 70, (2004), 033402. |
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"Theoretical studies of nano self-assembly", P. Alex Greaney , Ph. D. Thesis, University of California at Berkeley. (2003). |
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"Equilibrium analysis of lattice-mismatched nanowire heterostructures", E. Ertekin, P. Alex Greaney, T. D. Sands, and D. C. Chrzan DC, Materials Research Society Proceedings, Vol.737, Quantum Confined Semiconductor Nanostructures Symposium, Boston, MA., USA, Dec. 2002, 769-74. |
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"Self-assembled nanostructures through wavelength-controlled spinodal decomposition", P. Alex Greaney, D. C. Chrzan, B. M. Clemens, and W. D. Nix, Applied Physics Letters, Vol. 83, # 7, (2003), 1364-6. |
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"Adatom transport on strained Cu(001): Surface crowdions", Wei Xiao, P. Alex Greaney, and D. C. Chrzan, Physical Review Letters, Vol. 90, (2003), 156102. |
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"Continuum simulation of dislocation dynamics: predictions for internal friction response", P. Alex Greaney, Lawrence H. Friedman, and D. C. Chrzan, Computational Materials Science, Vol. 25, (2002), 387-403. |
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"Amplitude dependent internal friction within a continuum simulation", P. Alex Greaney and D. C. Chrzan, Materials Research Society Proceedings , Vol.578, Multiscale Phenomena in Materials - Experiments and Modeling Symposium, Boston, MA, USA, 30 Nov.-2 Dec. 1999, 161-6. |