Etude des propriétés structurales et magnéto-optiques des films ultraminces déposés par épitaxie pseudomorphique

Abstract

In this work, we have investigated the structural and magneto-optical properties of the ultrathin films of Fe growth by pseudomorphic epitaxy on semi-infinite crystal of Cu(001) and given by the formula Fen/Cu(001) with (n=1, 2, 3…)which are used in technological applications, in particular in the field of Storage and magnetic recording, We have adopted a relativistic approach using DFT theorem with local spin density approximation (LSDA). The Spin-Polarized Relativistic (SPR) Linear Muffin-Tin Orbitals (LMTO) with the Atomic Sphere Approximation (ASA) method are used to calculate the structural properties which are determined from the relaxation by a process of optimization of the total energy as a function of the distance between the different atomic planes that constitute these films. The pseudomorphic crystalline structure found is body centered tetragonal (bct) with tetragonality ratio c/a larger than unity (dilated structure).The magneto-optical properties are studied from the polar magneto-optical Kerr effect spectra in the visible range.It spectrum was characterized by a negative peak in the range of the visible near E = 3.76 eV. The microscopic origin of the most interesting features of Kerr rotations are interpreted by interband transitions and the symmetries involved in this transitions are, in their majority, of the spin-flip type