Phase transitions in surface segregation of <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi mathvariant="normal">Pt</mi></mrow><mrow><mi mathvariant="italic">c</mi></mrow></msub></mrow></math></span><span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi mathvariant="normal">Ni</mi></mrow><mrow><mn>1</mn><mi mathvariant="normal">−</mi><mi mathvariant="italic">c</mi></mrow></msub></mrow></math></span> alloys from tight-binding Ising-model calculations

Bernard Legrand; Guy Tréglia; François Ducastelle

doi:10.1103/PhysRevB.41.4422

Phase transitions in surface segregation of ${Pt}_{c}$ ${Ni}_{1 - c}$ alloys from tight-binding Ising-model calculations

Bernard Legrand, Guy Tréglia, and François Ducastelle

Phys. Rev. B 41, 4422 – Published 1 March 1990

Abstract

The tight-binding Ising model coupled with a mean-field approximation formulated as an area-preserving map is applied to surface segregation of ${Pt}_{c}$ ${Ni}_{1 - c}$ alloys. It allows us to reproduce the striking experimental data available for the low-index faces and in particular the face-related segregation reversal observed when going from the (111) to the (110) face. Moreover, it predicts some spectacular phase transitions of the concentration profiles as a function of temperature and bulk concentration.