R. Q. Wu

Room-temperature ferromagnetism in carbon-doped ZnO

We report magnetism in carbon doped ZnO. Our first-principles calculations based on density functional theory predicted that carbon substitution for oxygen in ZnO results in a magnetic moment of 1.78

Magnetism in BN nanotubes induced by carbon doping

\mu_B

Cu-doped GaN: A dilute magnetic semiconductor from first-principles study

per carbon. The theoretical prediction was confirmed experimentally. C-doped ZnO films deposited by pulsed laser deposition with various carbon concentrations showed ferromagnetism with Curie temperatures higher than 400 K, and the measured magnetic moment based on the content of carbide in the films (

Ferromagnetism in Mg-doped AlN from ab initio study

1.5 - 3.0 \mu_B

Effects of edge passivation by hydrogen on electronic structure of armchair graphene nanoribbon and band gap engineering

per carbon) is in agreement with the theoretical prediction. The magnetism is due to bonding coupling between Zn ions and doped C atoms. Results of magneto-resistance and abnormal Hall effect show that the doped films are

Impact of oxide defects on band offset at GeO2/Ge interface

n

Glass forming abilities of binary Cu100-xZrx (34, 35.5, and 38.2 at. %) metallic glasses : A LAMMPS study

-type semiconductors with intrinsic ferromagnetism. The carbon doped ZnO could be a promising room temperature dilute magnetic semiconductor (DMS) and our work demonstrates possiblity of produing DMS with non-metal doping.

Possible graphitic-boron-nitride-based metal-free molecular magnets from first principles study

We performed ab initio calculation on the pristine and carbon-doped (5,5) and (9,0) BN nanotubes. It was found that carbon substitution for either a single boron or a single nitrogen atom in the BN nanotubes can induce spontaneous magnetization. Calculations based on density functional theory with the local spin density approximation on the electronic band structure revealed a spin polarized, dispersionless band near the Fermi energy. The magnetization can be attributed to the carbon 2p electron. Compared to other theoretical models of light-element or metal-free magnetic materials, the carbon-doped BN nanotubes are more experimentally accessible and can be potentially useful.

Manipulating absorption and diffusion of H atom on graphene by mechanical strain

First-principles calculations based on spin density functional theory are performed to study the spin-resolved electronic properties of GaN doped with 6.25% of Cu. The Cu dopants are found spin polarized and the calculated band structures suggest a 100% polarization of the conduction carriers. The Cu-doped GaN favors ferromagnetic ground state which can be explained in terms of p‐d hybridization mechanism, and a Curie temperature around 350K can be expected. These results suggest that the Cu-doped GaN is a promising dilute magnetic semiconductor free of magnetic precipitates and may find applications in the field of spintronics.

Electronic structures of β-Si3N4(0001)/Si(111) interfaces: Perfect bonding and dangling bond effects

Ab initio calculations based on spin density functional theory were carried out to investigate Mg-doped AlN as a possible dilute magnetic semiconductor. It was found that both Al vacancy and substitutional Mg impurity in AlN lead to spin-polarized ground states. However, sufficient Al vacancy concentration may be difficult to achieve under thermal equilibrium because of the high formation energy of Al vacancy. On the other hand, formation energy of Mg defect is fairly low and the authors’ calculations predict a ferromagnetic coupling among MgN4 tetrahedra. Based on the analysis on Cu-doped ZnO [L. H. Ye et al., Phys. Rev. B 73, 033203 (2006)], room temperature ferromagnetism can be expected in AlN doped with 7% of Mg which can be incorporated at a growth temperature of 2000K under N-rich condition.