Epitaxial growth of Fe on sulphur-passivated GaAs(100): a method for preventing As interdiffusion

Growth evolution and superparamagnetism of ultrathin Fe films grown on GaN(0001) surfaces

“…The monotonic increase in coercivity may be related to a structural change of the Fe ultrathin films. It has been shown by Anderson et al that the epitaxial quality of Fe/GaAs(001) degraded after about 12 ML 21. In analogy, the increase in the coercivity in our present study might be accounted for by the deterioration of the crystalline quality of the Fe/GaN(0001), as evidenced by the broadening of the RHEED spots at higher Fe coverage.…”

Bonding Character and Magnetism at the Interface Between Fe and MoS2 Nanosheets

“…In addition, the angular dependent HAXPES spectra (not shown) yield the ratio I S2 s / I Mo3 d slightly (by 5%) increasing at the take‐off‐angle TOA = 30° compared to TOA = 5°, thus indicating that S is bound to the bulk Fe atoms, as confirmed by HAXPES on Fe (not shown). Very similar effects have been previously observed in Fe/GaAs and Fe/InP systems, where S‐passivation (with about one monolayer of S) of GaAs and InP has been used prior to Fe deposition, in order to prevent reactions of Fe bonding with As and P . Upon Fe deposition at RT, in both cases a floating‐out of S on the top of the Fe overlayer has been observed, with Fe thicknesses of seven ML and 1.6 nm in Refs.…”

“…Upon Fe deposition at RT, in both cases a floating‐out of S on the top of the Fe overlayer has been observed, with Fe thicknesses of seven ML and 1.6 nm in Refs. , respectively. Likely, in our system a similar process occurs, where upon the Fe deposition S atoms tend to out‐diffuse from the interface.…”

“…, S atoms do not reach the surface. Moreover, Anderson et al identified the presence of polycrystalline disordered Fe‐Ga compound as the predominant phase at the Fe/GaAs interface, being in line with the tendency of the Fe atoms to bound with the Mo cation at the Fe/MoS 2 interface. A second S2s peak with BE ≈233.4 eV emerges upon Fe deposition (dark‐green line in Figure b. It can be attributed to S 6+ charge state, in FeSO 4 .…”

Distorted iron films onGaAs(001)−(4×6)

“…Complications to studies of this system, in the form of magnetically-dead layers arise from reaction of the iron with the GaAs to form a solid solution, Fe 3 Ga 2-x As x [7,8] at the interface and, depending on preparation conditions, to several tens of monolayers in thickness [7]. Two approaches exist to avoid forming this ternary phase at the interface: sulphur passivation [9,10] and Ga-enrichment of the GaAs surface by using the (4x6) reconstruction [11,12]. Both are aimed at reducing the availability of As for reaction with the Fe and at producing bcc-structured Fe films.…”