3d transition metal doped ZnO one-dimensional magneto-optical mechanism of nano-materials

Title: 3d transition metal doped ZnO one-dimensional magneto-optical mechanism of nano-materials Author: Fu-Chun Zhang Degree-granting units: Graduate School of Chinese Academy of Sciences (Xi'an Institute of Optics and Fine Mechanics) Keywords: ZnO;; density functional theory;; nanowires;; nanotubes;; 3d transition metal doped Abstract: Zinc oxide (ZnO) as an excellent piezoelectric and optical properties of Ⅱ - Ⅵ race wide band gap semiconductor materials, electrical, optical
Such as science and magnetism has broad Magnetic lifter application prospects. Particularly dilute magnetic semiconductor ZnO-based materials, due to the living room may have more than
In temperature T_c, a large magnetic ion solubility, transparency in the visible range and other characteristics, there is hope a new generation of information processing and storage
, Quantum computing and quantum communication and other areas of important material. In this paper, based on density functional theory within the framework of first-principles calculation
Method, systematic study of the ZnO nano-materials and 3d transition metal doped ZnO nano materials, one-dimensional geometry, electronic structure and magnetic
, Optical, electrical properties, ZnO-based analysis of the one-dimensional dilute magnetic semiconductors and magnetic materials, magnetic source coupling mechanism, and transition metal doped
One-dimensional ZnO nano-magnetic materials, electrical and optical properties for the prepared high-quality, high Curie temperature of the one-dimensional ZnO nano-magnetic
Material provides a theoretical basis. Paper's content and results are as follows: 1.ZnO material electronic structure theory
. Based on first-principles density functional theory calculations, comparative study of the ZnO material using different exchange-correlation function
The basic structure and properties. http://www.999magnet.com/products/131-magnetic-lifter The results show that the use of LDA + U and B3LYP exchange-correlation functional method is obviously superior to the use of GGA and
LDA calculations, LDA + U and B3LYP DFT calculated band gap value closer to the experimental value, but the LDA + U and B3LYP time-consuming to
Doubled, while the GGA by using the shortest. 2.ZnO nanowires and nanotube electronic structure and properties of the theory. By density
Functional theory study of ZnO nanowires and nanotube geometry, electronic structure and optical properties. The study found that as the ZnO nanowires
Size increases, the binding energy decreases, the system gradually becomes more stable structure. Charge density calculations show that the ZnO nano-
Line in the Zn-O covalent bond between the mainly based, with both ionic composition, pd orbital overlap with strong hybridization effects, the nano-
Line segregation of surface charge are out, the electron delocalization increases, Zn-O covalent decreased, plasma enhanced. ZnO nano-management on the calculation results
Results show that all configurations of the nanotubes from the original type folds into a cylindrical tubular structure, binding energy is negative, indicating that single-walled ZnO
Nanotubes can be stabilized there. Electronic structure calculations show that the ZnO nanotubes is a direct band gap of wide band gap semiconductor materials, band gap values
Are significantly larger than the body material; with the nanotube diameter increases, the valence band compared with the material significantly broadening and shift to lower energy side, in
Valence band top due to surface effects appeared defect state level; ZnO nanowires and optical properties of nanotubes results show that, with ZnO nano-
Line size and nanotube diameter decreases, the absorption spectra of the blue shift, and corresponds to the ultraviolet. 3.3d transition metal doped
ZnO nanowire hybrid magnetic, optical and electrical properties of the study. Based spin-polarized density functional theory calculations, the system of
The 3d transition metal doped ZnO nanowire geometry, electronic structure and magnetic, electrical and optical properties. Study, V-doped
System has only ferromagnetic coupling characteristics, Mn doped only with anti-ferromagnetic characteristics, while Cr, Fe, Co and Ni doping system to replace a different location
Correspond to different magnetic coupling characteristics, therefore, 3d transition metal doped ZnO nanowires with a wealth of magnetic phenomena, especially for Co
Doping, the coupling of the ferromagnetic semiconductor magnetic, magneto-optical theory predicts excellent performance, and anti-doping is the formation of ferromagnetic
Semi-metallic magnetic materials. The results show the optical performance, 3d transition metal doped ZnO nanowires did not affect the overall optical properties
, Mn, Fe, Co, Ni doping have taken place in the blue shift, Cr-doped red-shift occurred. 4.3d sodium transition metal doped ZnO
Nanotubes magnetic, optical and electrical properties of the study. Based spin-polarized density functional theory within the framework of first-principles calculation
Method to study the 3d transition metal doped ZnO nano-tube geometry, electronic structure and magnetic, electrical and optical properties. The results
That, V, Cr and Mn doped ZnO nanotubes more easily to form the ferromagnetic material, has a strong magnetic; Fe and Co doped ZnO nanotubes easier
Easy to form anti-ferromagnetic materials; and Ni-doped ZnO nanotubes anti-ferromagnetic properties of ferromagnetic properties is slightly more stable. Electronic structure calculations show that in
3d states near the Fermi level splits into delocalized triplet t_ (2g) and the local area of ​​the doublet e_g, there has been a strong feature of hybrid coupling; light
Properties of the results show, 3d transition metal doped ZnO nanotubes appeared in the ultraviolet region, three distinct peaks, near UV absorption edge
Occurred redshift, 400nm absorption peak at a certain blue-shift, and Mn, Fe, Co, Ni absorption peak intensity was enhanced, while the absorption of Cr
Income intensity weakened. Theoretical calculations show that 3d transition metal doped ZnO nanotubes is an excellent UV electronic materials. Degree Year: 2009