Diode Heterostructures with Narrow-Gap Ferromagnetic A³FeB⁵ Semiconductors of Various Conduction Type

Abstract

The diode structures with narrow-gap ferromagnetic A³FeB⁵ semiconductors in the function of only p-region (p-GaFeSb/n-InGaAs), only n-region (n-InFeSb/p-InGaAs), p- and n-regions (p‑GaFeSb/ n-InFeSb, p-GaFeSb/n-InFeAs) of the p–n junction were manufactured by the method of pulsed laser deposition in vacuum. Composition of the ferromagnetic semiconductor layers and their thicknesses determined by the results of X-ray photoelectron spectroscopy in total correspond to the technological information for diode structures. More specifically, thickness of the GaFeSb layer is 25–30 nm, thicknesses of the InFeAs and InFeSb layers is 35–40 nm. The iron content in InFeSb ranges from 25 to 35 at %. The GaFeSb layer contains from 15 to 41 at % of iron, while 35 at % of iron is registered in InFeAs layer. Presence of Fe‒As(Sb), In–Fe, and Fe–Ga chemical bonds was found at chemical analysis of the structures. Because of this, it may be assumed that, in the manufactured structures, the Fe atoms can displace the elements of III and V groups simultaneously. All the structures demonstrates the effect of negative magnetoresistance at sufficiently low potentials of observation of the effect (to 50 mV), in small magnetic fields (to 3600 Oe) and at high temperature of measurements. For the GaFeSb/InFeSb, GaFeSb/InFeAs diodes, the negative magnetoresistance was observed for the first time up to room temperature. The hysteresis form of the dependences of resistance on magnetic field suggests an effect of ferromagnetic properties of the narrow-gap semiconductor layers on the carrier transport in the structures.