Based on density functional theory, we have investigated the effects of in-plane biaxial strain on the electronic and magnetic properties of the two-dimensional GaN (2D GaN) with Ga- (VGa) or N-vacancy (VN). We considered two different levels of vacancy concentration, i.e., and . While the pristine GaN 2D structures are intrinsically semiconducting, the 2D GaN with VGa defects under tensile/compressive biaxial strains is metallic, except at a high compressive strain of 6%. In addition, the 2D GaN exhibits a strain-tunable magnetic property by introducing the VGa defects, where the magnetic moment can be modulated by applying a biaxial strain on the material. A compressive strain larger than 2% tends to suppress the magnetic effect. A drastic reduction of the total magnetization from 2.21 to 0.16 is clearly visible for a lower VGa concentration of . On the other hand, the 2D GaN with VN defects is nonmagnetic, and this behavior is not affected by the biaxial strain.
Strain-tunable electronic and magnetic properties of two-dimensional gallium nitride with vacancy defects
K. H. Yeoh, K.-H. Chew, T. L. Yoon, Rusi, D. S. Ong; Strain-tunable electronic and magnetic properties of two-dimensional gallium nitride with vacancy defects. J. Appl. Phys. 7 January 2020; 127 (1): 015305. https://doi.org/10.1063/1.5132417
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