Abstract
Temperature-concentration phase diagrams for are obtained by combining density functional theory (DFT) in the generalized gradient approximation (GGA) and in the GGA with Hubbard correction with the cluster expansion and Monte Carlo simulation technique. In the GGA, holes are delocalized over the Co layer, while in the charges on the Co layer completely localize, forming distinct and cations. The leading interactions in GGA are long-range in-plane electrostatics and relaxation effects, whereas in Co-Co interactions dominate. Comparison of ground states, -lattice parameter, and Na1/Na2 ratio with experimental results consistently suggests that GGA is a better approximation for .
8 More- Received 14 January 2008
DOI:https://doi.org/10.1103/PhysRevB.77.224111
©2008 American Physical Society