The composition dependence of magnetic, electronic and optical properties of Mn-doped SixGe1-x nanowires

作者：Wei, Jianglin; Lan, Mu; Zhang, Xi^*; Xiang, Gang^*

来源：Semiconductor Science and Technology, 2017, 32(7): 075005.

DOI：10.1088/1361-6641/aa6b94

• SiGe nanowire
• composition dependence
• magnetic semiconductor
• co-doping
• Mn dopant

Mn-doped SixGe1-x nanowires (NWs) with different Ge concentrations have been studied by first-principles calculations. It is found that the spin dependent energy bands of the NWs show rich variations both in bandgap width and type (from indirect to direct) as the Ge concentration changes. The Mn-doped SixGe1-x NWs exhibit half-metallic characteristics for all Ge concentrations, and the ground states of the NWs are found to be ferromagnetic (FM). The net magnetization mapping and spin density of states calculations reveal that Mn 3d electrons have a strong hybridization effect with nearest Ge 4p electrons, which results in the Ge's nontrivial contribution to the magnetic moment of the NWs. Further magnon dispersion studies show that the magnetic order stability of the NWs is influenced by Ge concentrations. Finally, the dependence of the optical properties of the magnetic NWs on the Ge concentration is demonstrated. Our results suggest that Mn-doped SixGe1-x NWs may be useful in spintronic and optoelectronic devices.

• 出版日期2017-7
• 单位四川大学