Dresden 2026 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 21: Phase Transformations II

MM 21.2: Talk

Wednesday, March 11, 2026, 10:30–10:45, SCH/A215

Chemoelastic effects, phase equilibria, and uphill diffusion in Cu-Pd nanoparticles — •Idan Klein, Feitao Li, and Eugen Rabkin — Department of Materials Science and Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel

We fabricated nanoparticles (NPs) of Cu-40 at.% Pd alloy via solid state dewetting and subsequent slow-cooling of Cu-Pd bilayers deposited on a sapphire substrate. We observed that some nanoparticles which experienced partial transformation from a disordered A1 FCC phase to the ordered B2 β-CuPd exhibited compositional discontinuity, with the ordered phase being richer in Pd. This compositional discontinuity was associated with fully or partially coherent interphase boundary. At the same time the FCC particles that did not experience any transformation, the fully transformed β-CuPd particles, and partially transformed particles with incoherent interphase boundary exhibited homogeneous distribution of the components. We developed a thermodynamic model which demonstrated that misfit-strain from the coherent interface influences the thermodynamics of the system, depressing the transformation temperature. Re-distribution of the components causes changes to the lattice parameter of each of the phases, mitigating the misfit between them, reducing free energy and encouraging the phase transformation.

Keywords: Solid State Dewetting; Order-Disorder; Misfit; Strain; Coherent