Fabrication and magnetic properties of nanostructured amorphous Nd–Co films with lateral modulation of magnetic stripe period

Tunable exchange bias-like effect in patterned hard-soft two-dimensional lateral composites with perpendicular magnetic anisotropy

“…Actually, we observe an "exchange bias The samples have been fabricated by the combination of electron beam lithography (EBL), sputtering deposition, and ion milling techniques similar to the process described in Ref. 25. The patterned microstructures consist of rectangular 300 Â 1000 lm 2 magnetic frames, where the central square area of 300 Â 300 lm 2 is filled with 3 lm diameter discs, in a square lattice with different lattice parameters L (6, 7.5, and 9 lm) and different thicknesses regarding to the rest of the layer [ Fig.…”

“…Depending on the thickness of the magnetic layer, the magnetic hysteresis loop of the system can change from a clear transcritical loop (a reduced in-plane remanent magnetization followed by an almost linear reversible region as the magnetization approaches to saturation) with remarkable PMA (Nb protected layer), to an in-plane uniaxial loop (etched layer) with a reduction in coercivity from 300 Oe to 50 Oe in agreement with previous results. 25,27,28 The reason for the in-plane uniaxicity comes from the co-sputtering deposition method 29 and its magnetic easy axis (E.A.) is parallel to the short side of the magnetic frames [ Fig.…”

“…The magnetic differences between the discs and the etched layer allow us to perform the following experiment to control the magnetization reversal in this last one: first, by the application of an in-plane saturating field (H ! 1500 Oe) we can orient the weak magnetic stripe domains in the discs along the field direction, 23,25 and second, measure the hysteresis loops of the etched layer in the in-plane E.A. direction with a field amplitude smaller than 150 Oe which, according to the hysteresis loops of the control layers shown in Fig.…”

Imprinted labyrinths and percolation in Nd-Co/Nb magnetic/superconducting hybrids

“…Superconducting transition temperature is T C % 7.55 K and Ginzburg-Landau coherence length, estimated from the temperature dependence of the upper critical field H c2 (T), is n GL ¼ 9 nm, typical of sputtering-grown Nb films in this thickness range. 15 The ferromagnetic layer in the hybrid bilayers is made of NdCo 5 , an amorphous alloy with saturation magnetization M S ¼ 1.4 Â 10 3 emu/cm 3 at 10 K. 16 Out of plane hysteresis loops present typical saturation fields H sat out-of-plane in the 5-10 kOe range, depending on sample thickness, well below the shape anisotropy field 4pM s ¼ 18 kOe indicating the existence of a moderate out-of-plane anisotropy K n within the layers. 16 The effective PMA constant, K n , can be estimated from H sat in-plane ¼ 25 kOe, the saturation field of an in-plane hysteresis loop measured in a 80 nm thick film, 16 3 .…”

Controlled nucleation of topological defects in the stripe domain patterns of lateral multilayers with perpendicular magnetic anisotropy

“…37 Then, several e-beam lithography, liftoff, and ion beam etching processes have been performed in order to create the desired thickness modulation over an extended sample area. 38 The result is a set of 70 μm ×70 μm Nd-Co squares with alternate linear regions of thickness t 1 = 50 nm and t 2 = 80 nm, width w/2, and lateral period w. The patterned grooves are parallel to one of the square sides, as sketched in Fig. 1(b) and, also, to the growth-induced easy axis.…”