Au-induced perpendicular magnetization in Fe films grown on Si(001)

Abstract

We report on Fe films grown on Au-buffered Si(001) showing perpendicular magnetization at ambient temperatures. The in-plane magnetization in ultra-thin Fe films grown at 150 K reorients irreversibly out-of-plane as a result of annealing close to room temperature. A Au cap layer which is expected to segregate to the top of the Fe film may be responsible for this behaviour. This hypothesis is based on the observation of an in-plane to out-of-plane reorientation of magnetization upon the growth of an ultra-thin Au cap layer on a slightly thicker Fe film. The origin of such a strong out-of-plane anisotropy of Fe induced by Au is discussed.

Magnetic coupling betweenFenanoislands induced by capping-layer magnetic polarization

“…The thickness dependence of the reorientation transition in Fe͑110͒ ultrathin films grown on W͑110͒ can be tailored by controlled modification of the surface (anisotropy) of the Fe films through the deposition of noble metal (Ag and Au) ovelayers. 13 An in-plane to out-of-plane reorientation of magnetization upon the growth of an ultrathin Au cap layer on a slightly thicker Fe film has been reported recently by Zavaliche et al 9 On the other hand it is well documented that a nonmagnetic metal in contact with a ferromagnetic one often displays magnetic order. [17][18][19] In such systems, the interaction between the electronic states of the various elements and the 3d states of the ferromagnetic metal plays a fundamental role.…”

“…The interplay between exchange interaction, (long range) dipolar interaction, and on-site magnetocrystalline anisotropy gives rise to a variety of magnetic phenomena with no counterpart in three-dimensional systems, such as perpendicular magnetic anisotropy [9][10][11] and magnetic reorientation transition. [12][13][14] The influence of various cover layers such as Au, Cu, Pd, and Ag on perpendicular magnetic anisotropy has been investigated in Co ultrathin films.…”

STM topography and manipulation of single Au atoms on Si(100)

“…2 Gold covered silicon surfaces also show interesting mesoscopic structures [3][4][5][6][7][8] as well as optical properties. 9 Furthermore, the presence of a gold monolayer on silicon has been shown to radically influence the growth process of silicon oxide, 10 iron, 11,12 and other more complex materials. [13][14][15] In recent years, thin films of Au on Si͑100͒ surface have been investigated at different coverages with different spectroscopic techniques but the description of such Au films is still extremely controversial.…”

Two‐Dimensional Self‐Organization of an Ordered Au Silicide Nanowire Network on a Si(110)‐16 × 2 Surface

“…Under appropriate growth conditions, the heterogeneous adsorption of molecular or magnetic films on these two chemically distinct Au silicide NW arrays may occur. Self‐assembled monolayers or other molecules are preferentially adsorbed on Au or Au silicide nanostructures;41 also, Fe films grown on an Au‐monolayer‐covered Si surface could suppress the formation of iron silicide to produce perpendicular magnetization at ambient temperatures 42. Therefore, such a well‐ordered 2D Au silicide NW network can serve as a versatile nanotemplate to fabricate highly integrated crossbar molecular‐electronic43 or magnetoelectronic44 circuits on a Si(110) substrate by the selective reactivity of organic molecules or magnetic metals on this mesh template.…”