Antisite-defect-induced surface segregation in ordered NiPt alloy
2003 (English)In: Physical Review Letters, ISSN 0031-9007, Vol. 90, no 2Article in journal (Refereed) Published
By means of first principles simulations we demonstrate that tiny deviations from stoichiometry in the bulk composition of the NiPt-L1(0) ordered alloy have a great impact on the atomic configuration of the (111) surface. We predict that at T=600 K the (111) surface of the Ni51Pt49 and Ni50Pt50 alloys corresponds to the (111) truncation of the bulk L1(0) ordered structure. However, the (111) surface of the nickel deficient Ni49Pt51 alloy is strongly enriched by Pt and should exhibit the pattern of the 2x2 structure. Such a drastic change in the segregation behavior is due to the presence of different antisite defects in the Ni- and Pt-rich alloys and is a manifestation of the so-called off-stoichiometric effect.
Place, publisher, year, edition, pages
2003. Vol. 90, no 2
energy electron-diffraction, transition-metal alloys, sandwich segregation, point-defects, pt50ni50
IdentifiersURN: urn:nbn:se:kth:diva-22181DOI: 10.1103/PhysRevLett.90.026105ISI: 000180444200032OAI: oai:DiVA.org:kth-22181DiVA: diva2:340879
QC 201005252010-08-102010-08-10Bibliographically approved