Multilayer Epitaxial Heterostructures with Multi-Component III-V:Fe Magnetic Semiconductors.

ABSTRACT

Three-layer structures based on various multi-component films of III-V semiconductors heavily doped with Fe were grown using the pulsed laser sputtering of InSb, GaSb, InAs, GaAs and Fe solid targets. The structures comprising these InAsSbFe, InGaSbFe and InSbFe layers with Fe concentrations up to 24 at. % and separated by GaAs spacers were deposited on (001) i-GaAs substrates at 200 °C. Transmission electron microscopy showed that the structures have a rather high crystalline quality and do not contain secondary-phase inclusions. X-ray photoelectron spectroscopy investigations revealed a significant diffusion of Ga atoms from the GaAs regions into the InAsSbFe layers, which has led to the formation of an InGaAsSbFe compound with a Ga content up to 20 at. %. It has been found that the ferromagnetic properties of the InAsSbFe magnetic semiconductor improve with an increasing SbAs ratio. It has been concluded that the indirect ferromagnetic exchange interaction between Fe atoms occurs predominantly via Sb atoms.