Structural and magnetic properties of the Ti/Fe multilayers

Abstract

The structure and magnetic properties of the rf-sputtered Fe/Ti multilayers with the fixed Ti-layer thicknesses (series 1: tTi=1 nm and series 2: tTi=2 nm) and the variable Fe-layer thicknesses (1 nm⩽tFe⩽6 nm) have been studied by the high-angle x-ray diffraction, transmission electron microscopy, conversion electron Mössbauer spectrometry and vibrating sample magnetometer. The results show that Fe layers with thicknesses less than 1 nm are alloyed forming an amorphous TiFe2 phase. As the Fe-layer thickness increases, the iron-rich crystalline Fe–Ti alloy is formed at the interface and, finally, the pure crystalline α-Fe and Ti layers appear in the center of the individual subsystems. The spin orientation in Fe layers is then strongly aligned in the film plane. However, in the interfacial region, perpendicular spin orientation is evidenced. This perpendicular magnetic anisotropy is associated to the Fe-rich alloy at the interface and is discussed in terms of reduced symmetry effects on the band structure of the 3d(Fe)-itinerant electrons.

Structural and magnetic study of MBE-UHV evaporated (Fe/Y) multilayers

“…The positive value of K S reflects a perpendicular magnetic anisotropy, while the negative value of K V reflects the in-plane anisotropy of the volume. These values of K S and jK V j are larger than those deduced for (Fe/Ti) and (Fe/V) multilayers [4,5] at 300 K.…”

“…The RHEED patterns were also recorded during the deposition of two multilayers (Fe 0.5 nm/Y 0.5 nm) 5 and (Fe 1.0 nm/Y 1.0 nm) 5 . For other samples, the Fe layer thickness t Fe is varying between 0.5 and 6.0 nm while the Y layer thickness t Y is fixed to 1.0 nm.…”

“…The positive value of K S then has been attributed to the Fe surface because in the vicinity of the Fermi level the OPS symmetry states are dominant in comparison to those of the in-plane states (IPS). This arguments were used to interpret the perpendicular magnetic anisotropy observed in (Fe/Ti) multilayers [5].…”

“…The spin orientation in the interfaces has been described in terms of the electronic origin for the multilayers Fe/X where X is Sc, Ti, V, Y, Lu, y A planar magnetic anisotropy is predicted [3] and has been observed in some (Fe/Y) systems [4]. Experimentally it has been observed a random spin orientation at room temperature in Fe/Ti [5] and in Fe/V [6], which was attributed to the topmost of the Fe layers, but not to the Fe-V alloy at the interface [6].…”

Nanometer Scale Tomographic Investigation of Fine Scale Precipitates in a CuFeNi Granular System by Three-Dimensional Field Ion Microscopy

“…and the structural parameters of the precipitates were deduced from magnetization curves and Mössbauer spectra. In addition, Mössbauer spectroscopy has made possible a link between structural and magnetic observations~Eymery et al, 1983Richomme et al, 1996;Fnidiki et al, 1998;Lemoine et al, 1999;Juraszek et al, 2000;Duc et al, 2002!. Those magnetic analyses revealed the presence of fine body-centered cubic a-Fe precipitates with a radius slightly larger than 1 nm. In Martins and Missel~1999!, some spinodally decomposed Fe,Ni!-rich zones were observed by high-resolution transmission electron microscopy~HRTEM!…”