Epitaxial Fe₃Si films on GaAs(100) substrates by means of electron beam evaporation

Abstract

This paper presents results on the preparation, structural, electrical and magnetic properties of Fe(3)Si films as a representative for a Heusler alloy-like compound which are known as half-metallic materials with ferromagnetic behaviour. The films have been prepared by means of ultra-high vacuum (UHV) electron beam evaporation with the aim of achieving epitaxial growth on GaAs(100) substrates. The main focus of this work is the structural characterization of the Fe(3)Si films grown on GaAs by means of high resolution transmission electron microscopy (TEM) to confirm the epitaxial growth. For Fe(3)Si with a composition in the vicinity of stoichiometry an almost lattice-matched growth on GaAs(001) has been observed characterized by a high crystalline quality and a good interface perfection. Besides the studies on cross-sectional samples by TEM data from reflection high energy electron diffraction (RHEED) and x-ray diffraction (XRD) were also included into the discussion. The electrical and magnetic parameters of the films studied are found to be in good agreement with data reported for the best Fe(3)Si molecular beam epitaxy (MBE) layers. As evidenced by x-ray diffraction, transmission electron microscopy, resistivity and magnetic measurements, we find an optimum growth temperature of 280-350 degrees C to obtain ferromagnetic layers with high crystal and interface perfection as well as a high degree of atomic ordering.

Large Nonreciprocal Propagation of Surface Acoustic Waves in Epitaxial Ferromagnetic/Semiconductor Hybrid Structures

“…Fe 3 Si is a binary Heusler-like ferromagnetic metal which has attracted interest as possible component in magneto-electronic devices. 30,31 As its cubic crystal structure is almost lattice-matched to the GaAs substrate (mismatch ≤ 0.01%), it is possible to grow epitaxial films with high interfacial perfection and structural quality, [32][33][34] thus leading to narrow ferromagnetic resonance (FMR) lines 35,36 characterized by damping coefficients as low as α ≈ 3 × 10 −4 . 37…”

The effect of Fe-coverage on the structure, morphology and magnetic properties of α-FeSi2nanoislands

“…To this day, several Fe-silicide structures have been reported. At the Fe-rich side of the binary phase diagram, metallic as well as ferromagnetic Fe 5 Si 3 and Fe 3 Si (DO 3 structure) [8,9] have already been established as key materials for spintronics [10][11][12], whereas ε-FeSi is a semimetal with a cubic B20 structure [13]. The Si-rich side of the phase diagram contains several variants of a disilicide stoichiometric compound, such as the high-temperature tetragonal metallic α-FeSi 2 phase [14], with applications as an electrode or an interconnect material [15], and the orthorhombic semiconducting β-FeSi 2 phase [16], which due to its direct band gap is an interesting candidate for thermoelectric, photovoltaic and optoelectronic devices [17]; there are also metastable metallic γ -FeSi 2 and s-FeSi 2 [2].…”

Strong crystal anisotropy of magneto-transport property in Fe3Si epitaxial film

“…The structural, transport, and magnetic properties of the Fe 3 Si/GaAs heterostructures have been studied [1][2][3][4][5][6][7]. Fe 3 Si is a ferromagnetic material that could be a promising candidate for injections of spin-polarized electrons from a ferromagnet into a semiconductor [8].…”