Fluorination induced half metallicity in two-dimensional few zinc oxide layers.
We systematically explore the stability, bonding characteristics, and electronic and magnetic properties of two-dimensional (2D) few zinc oxide layers (few-ZnOLs) with or without fluorination by using density functional theory approach. The pristine few-ZnOLs favor stable planar hexagonal structures, which stem from their unique bonding characteristics: The intralayer Zn-O interaction is dominated by covalent bonding while the interaction between layers is weak ionic bonding. Furthermore, we demonstrate that fluorination from one side turns the planar few-ZnOLs back to the wurtzitelike corrugated structure, which enhances the stability of the 2D ZnO films. The fluorinated few-ZnOLs are ferromagnets with magnetic moments as high as 0.84, 0.87, 0.89, and 0.72 mu(B) per unit cell for the number of layers of N=1, 2, 3, and 4, respectively. Most interestingly, the fluorination can also turn few-ZnOLs from semiconductor into half metallicity with a half-metal gap up to 0.56 eV. These excellent electronic and magnetic properties may open 2D ZnO based materials great opportunity in future spintronics.
Department of Physics, Southeast University, Nanjing 211189, People's Republic of China.
Qian
Q
Chen
Jinlan
J
Wang
Liyan
L
Zhu
Shudong
S
Wang
Feng
F
Ding