Ab initio calculation of structural and magnetic properties for Fe mono- and bilayers on Mo(110)

The atomic structures were optimized and magnetic moments calculated for the pseudomorphic Fe overlayers on Mol(1 1 0) substrates employing the all-electron full-potential linearized augmented plane-wave (FP-LAPW) method. Three slabs were considered: (i) 5 monolayer (ML) Mo(1 1 0) substrate, (ii) and (iii) 1 and 2ML pseudomorphic Fe overlayers on each side of 5 ML Mo(1 1 0) substrate. We found that for the bare Mo substrate, the top Mo-Mo interlayer spacing is contracted by 4.8% with respect to the theoretical bulk Mol(1 1 0) interlayer distance of 2.338 Angstrom. For the I ML Fe coverage, the Fe-Mo interlayer spacing has a contraction of 10.3% with respect to the calculated bulk Mol(1 1 0) interlayer spacing, while, for the 2ML Fe. it is reduced by 9.5%. The Fe-Fe interlayer spacing is also contracted by as much as 11.4% with respect to the theoretical bulk Fel(1 1 0) interlayer distance of 3.004 A. The inner Mo-Mo interlayer spacings are slightly expanded(<0.5%). The magnetic moment for the 1 ML Fe overlayer on top is enhanced to 2.59 mu(B), compared to the bulk value of 2.2 mu(B). For 2 ML Fe coverage, the magnetic moments are 2.81 mu(B) and 2.32 mu(B) for the surface and interface Fe layers, respectively. (C) 2000 Elsevier Science B.V. All rights reserved.