Effect of oxygen pressure on the texture of a magnetite film grown by reactive deposition on a SiO2/Si(001) surface

Crystal texture-dependent magnetic and magnetotransport properties of half-metallic Fe3O4 films grown on oxidized Si substrates by reactive deposition

“…The height of the largest grains is comparable to the film thickness of 75 nm, while their lateral dimensions (22 ± 3 nm) are approximately threetimes smaller. Obviously, that these grains have the predominant (311) orientation found from the analysis of the RHEED pattern for this film [23] and confirmed by the XRD study, Fig. 1(e).…”

“…The same MR value had a film deposited by magnetron sputtering at RT [28]. As in [27], smaller MR values for films grown at low pressures (110 -6 Torrand 1.510 -6 Torr) are explained by the presence of the paramagnetic phase FeO, the Debye ring from which we observed by RHEED during film growth [23]. In contrast to the Fe 3 O 4 film deposited at RT in [27], the films in this work were grown on a hot substrate (T sub =300°C) and had (311) and (110) textures.…”

“…1(e). Moreover, there is an indirect confirmation based on the observation of diffusion rings from wustite (FeO) at the initial stage of growth [23]. The observed diffractionrings from magnetite after deposition are associated with the transmission diffraction of electronsin the more oxidized surface layer of the film(grains) consisting of magnetite.…”

“…Lateral grain sizes increase by ~ 2 timescompare with the previous filmand reach 49 ± 5 nm. According to the analysis of the RHEED pattern [23], this film has the (110) texture. It is assumed that an increase in the O 2 pressure leads to an increase in the diffusion mobility of the adsorbates on {110} faces that have less free energy than the {311} faces.…”

“…Since, in a certain range of oxygen pressure, the formation of the Fe 3 O 4 phase occurs predominantly, a detailed study of the properties of the magnetite films as a function of pressure is very interesting. We have found [23] that, with some pressure variation, a preferred orientation of crystallites appears in the polycrystalline Fe 3 O 4 film. This structural change depending on the oxygen pressure was also observed in X-ray spectra [2,24].…”