Anomalous Hall measurements of Mn delta-doped GaN grown by molecular beam epitaxy
Cha-Her Lin1*, Paritosh Vilas Wadekar1, Yuan-Ting Lin1,2, Che-Min Lin1, Ching-Wen Chang1,3, Quark Yung-Sung Chen1,4, Tsan-Chuen Leung5, Cheng-Maw Cheng1,6, Li-Wei Tu1,7
1Department of Physics and Center of Crystal Research, National Sun Yat-Sen University, Kaohsiung, Taiwan
2Epistar Corporation, Tainan Science Park, Tainan, Taiwan
3Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Austin, USA
4Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, USA
5Department of Physics, National Chung Cheng University, Chiayi, Taiwan
6National Synchrotron Radiation Research Center, Hsinchu, Taiwan
7Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Kaohsiung, Taiwan
* Presenter:Cha-Her Lin, email:chaherlin@gmail.com
A gallium nitride (GaN) doped with manganese (Mn) diluted magnetic semiconductors (DMSs) system was grown by plasma-assisted molecular beam epitaxy. Two of the goals in DMSs field are keeping high spin ordering up to room temperature while also preserving semiconductor properties of the materials. GaN doped with Mn is one of promising system to satisfy the goals and predicted by calculation. However, doping more Mn is not as easy as ideal. In this study, homogeneous- and δ-doping process were reported. The results show that Ga, Mn alternative δ-doping gives no second phases and 1.54% Mn was doped. In δ-doped sample, anomalous Hall effect is observed because of strong p-d exchange interactions between 2p orbital of nitrogen derived holes in the valence band and the 3d spins of localized Mn. The results in this study are supported by temperature dependent resistivity measurements, Hall measurements, superconducting quantum interference device magnetometer, and density functional theory calculations.
Keywords: diluted magnetic semiconductor, (Ga,Mn)N, delta doping, density functional theory, molecular beam epitaxy