Structural transformation and spin-reorientation transition in epitaxial Fe/Cu3Au(100) ultrathin films

Abstract

The magnetic properties, morphology, and crystallographic structure are studied for Fe films on Cu 3 Au͑100͒ grown at room and low temperature, using in situ magneto-optical Kerr effect, scanning tunneling microscopy, and electron diffraction techniques. At Tϭ160 K a spin-reorientation transition from perpendicular to in-plane magnetization occurs in films with Fe coverages starting from a critical thickness of 3.5 and 5.5 ML for room-temperature and low-temperature growth, respectively. Close to the critical thickness we observe an fcc-bcc structural transformation. The spin-reorientation transition is shown to be correlated to this structural change. This correlation may be explained by a drastic reduction of the perpendicular anisotropy induced by the fcc-bcc structural transformation.

Magnetization Reversal Behaviour of Planar Nanowire Arrays of Fe

“…Our observation is in line with the crystal structure and symmetry reported for the interfaces Fe form with oxides [19]. It is also known that the epitaxial strain induced by the interfaces could stabilize the metastable fcc-Fe phase [20] which remains stable up to a few monolayers of Fe (typically 3-6 ML of Fe). However, we could not identify any regions with fcc-Fe structure in the Fe-NW arrays used in the present study.…”

Description of giant changes of domain sizes in ultrathin magnetic films

“…There are different methods for the anisotropy engineering, changing, e.g. : (i) magnetic film thickness, d [1]; (ii) temperature [2][3][4]; (iii) buffer morphology, roughness [5][6][7]; (iv) film structure [8,9] or structure of the cover layer [10][11][12]; (v) composition [13,14]; (vi) surface-interface roughness [15]. The reorientation phase transition (RPT) from easy magnetization plane into easy magnetization axis can be realized.…”

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

“…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]. To identify the structural properties of the films, the crystalline structure and interlayer distance of the alloy films were performed via the low energy electron diffraction (LEED) and LEED I(E) in the kinematic approximation [15][16][17][18]. In addition, the study of the magnetic hysteresis loops was carried out by means of magneto-optical Kerr effect (MOKE) in polar and longitudinal configurations quasi-simultaneously with benefit of the lock-in technique to investigate the evolution of SRT with variation of alloy concentration of the films.…”