Anisotropic transport behavior in ultrathin epitaxial Fe films on vicinal oxide substrates

Abstract

Step-induced anisotropy of electron transport in ultrathin Fe film was investigated. The Fe films ͑2 and 10 nm͒ were deposited on vicinal MgO ͑100͒ substrate using molecular-beam epitaxy. It is found that the films with a thickness of 10 and 2 nm are continuous and discontinuous, respectively, which was determined from their resistivity values, the temperature dependency of the resistivity and the V-I curve. The enhanced magnetoresistance in the continuous and the discontinuous films was observed when the current flows parallel and perpendicular to the miscut direction, respectively. We suggest that the atomic steps in the continuous films nucleate additional domain walls acting as scattering centers and the extra scattering was introduced for the current perpendicular to the step edges. The mechanism of the influence of the atomic steps on the electron-transport properties is different in the continuous and discontinuous films. We further suggest that in the discontinuous films, the atomic steps result in the anisotropic growth of the islands and the anisotropy in the transport behavior as a consequence.

Effect of carbon and post-annealing treatment on magnetic properties of high-quality iron thin films

“…Recently, iron films are subject of intense research work and there are many reports on the epitaxial growth and magnetic properties of Fe films [1][2][3][4][5][6]. Up to now, most of Fe films were deposited by molecular beam epitaxy (MBE) [18][19][20][21][22][23] and various materials (semiconductors, metals and insulators) have been selected as substrates due to their specific properties, such as lattice match, crystalline quality, thermal stability, etc. [7][8][9][10][11][12][13][14][15][16][17] For the magnetic properties, Shiratsuchi et al [17] have investigated the effect of substrate inclination on the inplane magnetic anisotropy of ultrathin Fe films grown on Al 2 O 3 (0 0 0 1) using MBE.…”

Self-patterned oxide nanostructures grown by post-deposition thermal annealing on stepped surfaces

“…step-bunching) [9,10], in order to generate self-organized nanostructures such as ordered arrays of nanodots [11,12] or nanowires [13]. New properties of these self-organized structures on stepped surfaces have been reached for many applications in optics [14][15][16], electronics [17][18][19] and magnetism [20][21][22]. Vicinal surfaces are also used to decrease the defect density as misfit dislocations [23][24][25] or antiphase domain boundaries [26,27], or may be used to select inplane crystallographic variants [28,29].…”