Thermal and irradiation induced interdiffusion in magnetite thin films grown on magnesium oxide (001) substrates

Interface Properties of Single and Bi-Layer Fe3O4Films Grown on MgO(001) Studied by RBS and Channeling Experiments

“…We have recently investigated the surface and interface stoichiometry and crystalline quality of both singleand bi-layer MBE magnetite films using the Rutherford backscattering spectrometry (RBS) and RBS-channeling experiments (RBS-C) [6,7]. The RBS data obtained for the as-grown films (with a thickness of 10-20 nm) confirmed the earlier observations by LEED and CEMS, e.g.…”

“…We note that the RBS experiments were performed about one week after the samples were exposed to air. Unlike the thin magnetite films (d = 10 nm) [6,7], no presence of magnesium was found in the surface layer of the Fe 3 O 4 films deposited directly on MgO substrates indicating no segregation of Mg atoms to the surface for the thick films exposed to air in a short time. However, a small amount of Mg outdiffusion was found at the interface leading to a spinel-type composition ((Fe 1−x Mg x ) 3 O 4 ) of the interface zone (with a thickness d < 5 nm and the x content is x = 5-10%).…”

“…The RBS and RBS-C experiments were performed at the Institute of Nuclear Physics of the University Frankfurt/Main. Details of the experiment conditions for RBS and RBS-C experiments have been already reported earlier [6,7]. For the data evaluation the computer code SIMNRA [9] was used taking into account the electronic stopping power data by Ziegler and Biersack, Chu + Yang's theory for electronic energy-loss straggling and Andersen's screening function to the Rutherford cross--section.…”

“…However, the stoichiometric surface Fe 3 O 4 layer of the bi-layer films is well preserved upon annealing and ion irradiation. Also, the Fe buffer layer has become oxidized completely upon annealing while it still existed upon ion irradiation although its thickness was decreased [7].…”

Modifying magnetic properties of ultra-thin magnetite films by growth on Fe pre-covered MgO(001)

“…24 The magnesium interdiffusion can be reduced, and higher annealing temperatures for magnetite are possible if iron buffer layers are deposited on the MgO substrate prior to the deposition of the magnetite films. 25 Here, a 10 nm iron film functions as a sacrificing layer that is completely oxidized after the annealing process at higher temperatures, while the surface near region of the 10 nm overlaying magnetite film remains unaffected by the Mg interdiffusion. Another effect of these iron buffer layers is the reduced formation of anti phase boundaries (APBs), 26 which are known to have significant influence on the magnetic properties of magnetite.…”