Structure and magnetism of ultrathin Co and Fe films epitaxially grown on Pd/Cu(001)

A mode-of-growth-dependent magneto-optical response from ultrathin Co films on Pd surfaces

“…The growth of Co on Pd(0 0 1) is found to be pseudomorphic and close to the layer-by-layer mode up to three monolayers (ML) [9,10]. At the initial stage of growth, ML-thick Co patches are formed, as it is confirmed by Fig.…”

“…The offset signal obtained by extrapolation of the Kerr rotation measured above the thickness of 2-3 ML to zero Co thickness is of the same sign as the rotation measured on the 'reference sample' (i.e., of the 5-10 ML of Co on Pd). This offset is equivalent to the Kerr rotation from 2-3 ML of Co [9]. The larger offset signal (equivalent to the Kerr rotation from 3.4 ML of Co) was detected for the Pd(1 1 1) substrate.…”

“…For a given magneto-optical geometry (i.e., the angle of incidence and the incident polarization of light), the slopes of the Kerr observables, rotation and ellipticity, versus thickness of the ferromagnetic film grown on a nonmagnetic substrate originate first in magnetism and optics of the films itself, and second in the optical permittivity of the substrate. Extrapolation of the linear variation of the Kerr observables to zero thickness results in an offset signal which can be either positive or negative, which means, respectively, of the same or opposite sign with respect to the signal from the thicker films [7][8][9]. The offset magneto-optical signal is attributed to a contribution from the interface region between the film and the substrate.…”

“…The Co films on Pd(0 0 1) do not show PMA and the polar Kerr signal is not detected for uncovered Co films. In our previous work we studied longitudinal Kerr rotation with p-polarized incident light for Co films grown on the Pd(0 0 1) substrate [9]. The present longitudinal experiments were performed for the same photon energy of 1.84 eV and for the identical geometry (i.e., for the p-polarized laser beam incident at 67°).…”

Ferromagnetism of Pd(001) substrate induced by antiferromagnetic CoO

“…Much attention has been paid to the magnetic properties of Pd: it was shown that the effect of ferromagnetism in Pd can be achieved by reduced dimensionality [8,9] and/or by quantum well states formed in ultrathin Pd films [10]. It is also well known that the neighboring 3d-ferromagnet can spin-polarize a nonmagnetic metal like Pd [11] only to understand the mechanism behind such spin-polarization effect but also for possible applications [12][13][14]. Especially, the magneto-optical Kerr effect (MOKE) measurements provide valuable information about such systems because the magneto-optical response from the ferromagnet/Pd interface is large [14][15][16][17].…”