Spontaneous L1(2) order at Ni(90)Al(10)(110) surfaces: an x-ray and first-principles-calculation study.
We have combined x-ray diffraction studies with first-principles calculations to study the interplay between segregation and ordering at the (110) surface of Ni(90)Al(10). We find a L1(2)-ordered monolayer at the surface. The observed ordering as well as recently reported Al segregation at the surface are explained in a consistent picture. A delicate competition between the tendency for Al segregation and ordering in the Ni-Al system induced by the symmetry break at the surface stabilizes a long-range ordered surface in the entire concentration range c(Ni)>0.75.
Drautz
R
R
Max-Planck-Institut für Metallforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany.
Reichert
H
H
Fähnle
M
M
Dosch
H
H
Sanchez
J M
JM