Facet-controlled phase separation in supersaturated Au-Ni nanoparticles upon shape equilibration

0449995 - ÚFM 2016 RIV US eng J - Článek v odborném periodiku
Herz, A. - Friák, Martin - Rossberg, D. - Hentschel, M. - Theska, F. - Wang, D. - Holec, D. - Šob, Mojmír - Schneeweiss, Oldřich - Schaaf, P.
Facet-controlled phase separation in supersaturated Au-Ni nanoparticles upon shape equilibration.
Applied Physics Letters. Roč. 107, č. 7 (2015), art.n. 073109. ISSN 0003-6951. E-ISSN 1077-3118
Institucionální podpora: RVO:68081723
Klíčová slova: GENERALIZED GRADIENT APPROXIMATION * NANOPOROUS GOLD NANOPARTICLES * AUGMENTED-WAVE METHOD * ELASTIC-CONSTANTS * BILAYER * NICKEL
Kód oboru RIV: BM - Fyzika pevných látek a magnetismus
Impakt faktor: 3.142, rok: 2015

Solid-state dewetting is used to fabricate supersaturated, submicron-sized Au-Ni solid solution particles out of thin Au/Ni bilayers by means of a rapid thermal annealing technique. Phase separation in such particles is studied with respect to their equilibrium crystal (or Wulff) shape by subsequent annealing at elevated temperature. It is found that {100} faceting planes of the equilibrated particles are enriched with Ni and {111} faces with Au. Both phases are considered by quantum-mechanical calculations in combination with an error-reduction scheme that was developed to compensate for a missing exchange-correlation potential that would reliably describe both Au and Ni. The observed phase configuration is then related to the minimization of strongly anisotropic elastic energies of Au- and Ni-rich phases and results in a rather unique nanoparticle composite state that is characterized by nearly uniform value of elastic response to epitaxial strains all over the faceted surface. The same conclusion is yielded also by evaluating bi-axial elastic moduli when employing interpolated experimental elastic constants. This work demonstrates a useful route for studying features of physical metallurgy at the mesoscale.
Trvalý link: http://hdl.handle.net/11104/0251465