On the variation of magnetic anisotropy in Co/Pt(111) on silicon oxide

Abstract

The structural properties and magnetic anisotropy of Pt/Co/Pt trilayers grown on thermally oxidized (Si/SiO2) and naturally oxidized silicon (Si/Siox) are presented. Although similar substrates and identical preparation conditions are used distinct differences in the structural composition are found which stem from the Pt seed layer created via ion assisted sputtering. While for thermal oxidized Si a Pt/Co/Pt trilayer is formed, for systems grown on naturally oxidized Si a complex PtSi alloy formation within the seed layer is observed as a consequence of the high ion energies of ion assisted sputtering. The composition of the PtSi alloy varies along the growth direction with a low Si content at the interface to Co and the lattice constant is similar to bulk Pt. The latter provides a much higher magnetic interface anisotropy constant compared to Pt/Co/Pt on thermal oxidized Si of about 0.9 mJ/m2 which is comparable to the highest values found for MBE grown Co on single crystalline Pt(111).

Employing soft x-ray resonant magnetic scattering to study domain sizes and anisotropy in Co/Pd multilayers

“…In the thickness range below t Critical the slope of the plot is equal to the bulk anisotropy K 1V = 0.93 ± 0.04 MJ/m 3 while the intercept gives twice the interface anisotropy K s = 0.14 ± 0.02 mJ/m 2 . The values are in good agreement with measurements of single and multilayer films [37,55,56]. Hence it must be concluded that for t < t Critical our model gives a very good agreement with what can be expected for the multilayers while for t > t Critical the assumption for deducing the anisotropy has to be put into question.…”

“…The resonant scattering amplitude f n = f charge n + f magnetic n contains a charge contribution and a magnetic scattering contribution, where the charge contribution corresponds to a nonresonant (classical Thomson scattering) as well as a resonant charge term. The charge contribution f charge n can be assumed to be constant and can be neglected for the multilayer, as correlations of charge inhomogeneities on the length scale of 100 nm do not exist in the sample under investigation (grain sizes 10 nm [37,38] (c) Intensity profiles extracted from the diffraction pattern via radial integration (colored symbols). We observe a shift of the peak position Q max (black horizontal arrow), as well as a decrease of the scattering intensity and an increase of peak width.…”

Morphological stripe-bubble transition in remanent magnetic domain patterns of Co/Pt multilayer films and its dependence on Co thickness

“…At some critical thicknesses t Co , the magnetization changes its preferential orientation due to the predominance of shape anisotropy over the magnetocrystalline and interface anisotropies, and vice versa. If the thickness t Co of a single Co layer is below ∼16 Å, 1 the interface anisotropy overcomes the shape anisotropy, resulting in an OOP magnetization independent of the number of repeats N [4,7,[33][34][35][36][37][38][39][40]. However, if the Co thickness is larger than ∼16 Å, the shape anisotropy, which is constant and equal to 2πM 2 S in the low thickness regime (where M s is the magnetization at saturation) [41], starts to dominate the interface anisotropy, which scales with the inverse thickness [7], and the magnetization turns IP.…”

Impact of Symmetry on Anisotropic Magnetoresistance in Textured Ferromagnetic Thin Films

“…The preparation and compositional structure of the Pt=Ni=Pt films is similar to the one for Pt=Co=Pt [31,66]. The structural characterization (Supplemental Material I [67]) particularly reveals that the grain size, crystallinity, and interfacial properties are independent on the Ni thickness enabling a thorough interpretation of the MR behavior.…”