Spark plasma sintering-assisted synthesis and high-Tc ferromagnetism of Mn-doped SiGe alloys

Abstract

In this work, Mn-doped SiGe alloys with high Curie-temperature (TC) ferromagnetism are synthesized via spark plasma sintering (SPS). The structural characterizations indicate that the Mn-doped samples are composed of strained Si0.25Ge0.75 crystals due to the incorporation of substitutional Mn dopants in the SiGe lattice. The magnetization characterizations and X-ray magnetic circular dichroism (XMCD) measurements show that the Mn-doped samples exhibit Mn concentration-dependent ferromagnetism up to room temperature, owing to the spin and orbit magnetic moment contribution from the substitutional Mn acceptors. Furthermore, the magneto-transport measurements reveal anomalous Hall effect and complex magnetoresistance in the ferromagnetic Mn-doped samples. This study gives insight into the fabrication and magnetic properties of Mn-doped SiGe alloys prepared by SPS and may be useful for related spintronic applications.