Critical evolution of spin-reorientation transition in magneticCoxNi1−x/Cu

Abstract

The ultrathin Co x Ni 1Ϫx /Cu(100) alloy films with low Co concentration xр10% was prepared for probing the effect of the d-band filling on the magnetic behavior. The perpendicular magnetization was observed only for films with xϽ10%. The spin-reorientation transition from the in-plane to perpendicular orientation was found to be extremely sensitive to the Co concentration. The critical thickness for the spin reorientation transition was changed drastically from 7.5 to 17.5 ML by varying x from 0 to 8 %. Since no significant change in structure and surface morphology was accompanied, these findings may be attributed to the critical influence of the d-band filling on the magnetic anisotropy at variation of alloy composition.

Effect of magnetic alloying on magnetic anisotropy in ultrathin fcc Ni-like films

“…It becomes crucial to confirm the structural invariance on the variation of the alloy composition. In the previous study, we found that the crystalline structure, lattice constant, as well as morphology of Co x Ni 1Àx /Cu(1 0 0) and Fe x Ni 1Àx /Cu(1 0 0) are invariant with alloy composition [10,11,9]. In addition, all these alloy films behave like the Ni/ Cu(1 0 0) film.…”

“…No SRT was found for x > 6% with the coverage up to 20 ML. In comparison with Co x Ni 1Àx / Cu(1 0 0) [10] (open and solid triangles in Fig. 1), d c of the Fe x Ni 1Àx /Cu(1 0 0) alloy film is more sensitive to the content of Fe.…”

“…To deposit the films with desired and subtle-varied alloy composition is relevant to the study on the drastic variation of critical thickness for SRT. The coverage and alloy composition of the alloy films in our experiments can be precisely controlled in the co-deposition technique to an accuracy of 0.05 ML and ±0.5%, respectively [10,11]. Furthermore, Auger electron spectroscopy (AES) was employed for studying the chemical structure and for double check of alloy composition of the alloy films [10,12].…”

“…The coverage and alloy composition of the alloy films in our experiments can be precisely controlled in the co-deposition technique to an accuracy of 0.05 ML and ±0.5%, respectively [10,11]. Furthermore, Auger electron spectroscopy (AES) was employed for studying the chemical structure and for double check of alloy composition of the alloy films [10,12]. The medium energy electron diffraction (MEED) was taken for calibration of the film coverage as well as for providing an information of the morphology of the film surface [13,14].…”

Magnetic properties of ultrathin Co/Ni/Pt(111) films

“…Similar to the system of 1 ML Ni/ 1 ML Co/Pt(1 1 1) film, the variations of relative Co and Ni signals may be due to the intermixing of Co and Ni [7]. In the MOKE studies of Co x Ni 1Àx / Cu(1 0 0) system, the MO responses were strongly dependent on the concentration of Co [8]. After annealing, the film was irreversible with y K of about 0.06 at RT.…”