Magnetism of amorphous Ge1-xMnx magnetic semiconductor films.

Authors :: Deng, Jiang-xia
Tian, Yu-feng
Yan, Shi-shen
Cao, Qiang
Liu, Guo-lei
Chen, Yan-xue
Mei, Liang-mo
Ji, Gang
Zhang, Ze
Source :: Journal of Applied Physics; Jul2008, Vol. 104 Issue 1, p013905, 4p, 1 Diagram, 3 Graphs
Publication Year :: 2008
Abstract: Amorphous Ge<subscript>1-x</subscript>Mn<subscript>x</subscript> magnetic semiconductor films with high Mn concentrations were prepared on liquid-nitrogen (LN<subscript>2</subscript>)-cooled glass substrates by ultrahigh vacuum thermal coevaporation. Hysteresis loops measured at 5 K show coexistence of ferromagnetism and paramagnetism. The maximum Curie temperature of 220 K was found in Ge<subscript>0.48</subscript>Mn<subscript>0.52</subscript> film. Moreover, exchange bias occurs in magnetization hysteresis loops for samples with higher Mn concentrations, which can be explained by the antiferromagntic exchange coupling between ferromagnetic phase and antiferromagnetic phase. All the Ge<subscript>1-x</subscript>Mn<subscript>x</subscript> magnetic semiconductor films show semiconducting transport behavior and anomalous Hall effects below the Curie temperature, indicating carrier-mediated ferromagnetism. [ABSTRACT FROM AUTHOR]