First Principles Study of Cu-Embedded Ni(110) Surfaces

Abstract

The atomic geometries and electronic band structures of Cu-embedded Ni(110) surfaces were studied theoretically. First principles calculation with spin-resolved local density functional theory was applied to the Ni(110) surface, and one to four Cu-embedded Ni(110) surfaces in the 2×2 surface unit cell. The optimized structures for the Ni(110) surface showed that interlayer spacing between the first and the second layer shrunk 11.1% of the bulk distance, but the second and third layer spacing expanded by 2.9% in agreement with previous studies. For the Cu-embedded surfaces, embedded Cu atoms are 11-14 pm higher than the top Ni atoms, which is about four times larger than the difference of the atomic radii. The detailed band structures and corresponding local density of states (LDOS) were calculated. At the embedded Cu atom sites, the surface LDOS near the Fermi level was reduced in agreement with previous scanning tunneling microscopy observation. In addition, by increasing the number of Cu atoms in the top layer, magnetic moments were decreased near the surface regions.

First-Principles Study of Silicon-Embedded Ni(110)

“…6(a). The width of the 3d -derived bands at the surface layer was about 3.3 eV compared to 4.8 eV for the bulk Ni, again slightly narrowed due to the lack of counterpart, as discussed previously [12]. The PDOS at the top Ni sites for align, stagger, and separate are compared in Fig.…”

“…We first recalculated the Ni(110) surface and compared it to our previous study because we adopted an improved functional here [12]. Our calculation showed the layer spacing between the first to the second (d 12 ) shrunk by -10.48%, which is slightly improved from -11.10% in the previous calculation.…”