Experimental insight into the magnetic and electrical properties of amorphous Ge_1-xMn_x

Abstract

We present a study of the electrical and magnetic properties of the amorphous Ge_1-xMn_x.DMS, with 2% ≤ x ≤ 17%, by means of SQUID magnetometry and low temperature DC measurements. The thin films were grown by physical vapour deposition at 50°C in ultrahigh vacuum. The DC electrical characterizations show that variable range hopping is the main mechanism of charge transport below room temperature. Magnetic characterization reveals that a unique and smooth magnetic transition is present in our samples, which can be attributed to ferromagnetic percolation of bound magnetic polarons.

Keywords:

• Dilute magnetic semiconductor
• bound magnetic polaron
• ferromagnetic percolation
• localization

Classification:

• 40 Optical, magnetic and electronic device materials
• 107 Glass and ceramic materials
• 203 Magnetics / Spintronics / Superconductors
• 306 Thin film / Coatings

Acknowledgments

The authors would like to thank Dr Elena Olivetti for the XRD measurements and Dr Alfio Battiato for the XPS measurements.