High coercivity and perpendicular anisotropy in Co–Cu granular films

Property changes of electroplated Cu/Co alloys and multilayers by organic additives

“…However, considering the Cu content in Co layers, we expect lower magnetization and reduced demagnetizing field. It is known that the magnetization of Co/Cu alloy decreases linearly in proportion to the Cu concentration and the relation is given as dM/dC$À1.6 per added Cu, where C is the Cu concentration [15,18]. Considering $25% of Cu concentration and the resulting $40% reduction of the magnetization, the demagnetizing field $10 kOe agrees well with the prediction.…”

Growth-induced non-planar magnetic anisotropy in FeCoZr-CaF2 nanogranular films: Structural and magnetic characterization

“…Complementary structural, magnetic, and spectroscopic study of granular films enables a critical consideration of previously discussed reasons, [8][9][10][11][12][13][14][15] which might promote perpendicular anisotropy in the context of texture effects, surface oxidation of nanograins, composition of matrix, or the influence of substrate temperature during deposition. In particular, XRD analysis of the films with 58 x 73 does not indicate any preferred crystallographic orientation for bcc a-FeCo(Zr) nanograins that could cause the appearance of perpendicular magnetic anisotropy in these films.…”

“…7 Recent studies report on perpendicular magnetic anisotropy in granular composite films containing metallic nanograins embedded into non-magnetic (insulating) matrices. [8][9][10] It is worth noting that intrinsic growth-induced magnetic anisotropy is quite unusual phenomenon for granular films and was reported only for a few systems like granular Co x Ag 1Àx , 8 Co-Zr-O, 9 and Co-Al 2 O 3 films, [10][11][12] Co-rich Co-Ag and Co-Cu granular materials, 13,14 or for (Fe-Ni-Co)-fluoropolymer films. 15 At low content of metallic nanograins, when their volume fraction, f V , is lower than 0.5, the magnetizing process of granular films is usually considered as a coherent rotation of magnetic moments of single-domain superparamagnetic (SP) nanograins.…”

“…10-12. It is generally accepted that the origin of perpendicular magnetic anisotropy in granular films is related to a preferential arrangement of metallic nanograins in the direction perpendicular to the film surface, resulting in the growth of columnar-like nanograins or nanograin agglomerations. 10,12,14,17 Sun et al 9 attributed the appearance of columnar metallic nanograins to the oxygen-containing atmosphere during deposition and to oxygen presence in Co-Zr-O films that lead to surface oxidation of nanograins. However, the recent reports on Co-Al 2 O 3 , FeCoZr-Al 2 O 3 , and FeCoB-SiO 2 films sintered by similar ion-sputtering technology did not reveal a general relation of perpendicular magnetic anisotropy to the composition of nanograins and matrix as well as to the oxygen pressure in the deposition chamber.…”

High coercivity and giant magnetoresistance of CoAg, CoCu granular films

“…Recently, their high coercivity and GMR properties, which make them to have potential application as high-density recording media and various other devices, have also been studied widely [2][3][4]. Basically, these properties depend on particle size, anisotropy, interaction between particles, spin-dependence scattering on particles etc.…”