LOCAL AND NONLOCAL DENSITY-FUNCTIONAL STUDIES OF FECR

Local spin density approximation and generalized gradient approximation calculations are reported for ferromagnetic B2 FeCr. Both shear elastic constants are found to be positive, indicating metastability of the B2 structure. Both the moments of the Fe and Cr layers are ferromagnetically aligned, with the Fe moment being considerably depressed. This is in contrast to the behavior for thicker films. The evolution of the behavior as a function of the layer thickness is addressed using supercell calculations. It is found that Fe monolayers in bcc Cr are ferromagnetically aligned with the neighboring Cr moments, while thicker Fe layers are antiferromagnetically aligned with the adjacent Cr layers.