title: Effect on Electron Structure and Magneto-Optic Property of Heavy W-Doped Anatase TiO2.
abstract: The spin or nonspin state of electrons in W-doped anatase TiO2 is very difficult to judge experimentally because of characterization method limitations. Hence, the effect on the microscopic mechanism underlying the visible-light effect of W-doped anatase TiO2 through the consideration of electronic spin or no-spin states is still unknown. To solve this problem, we establish supercell models of W-doped anatase TiO2 at different concentrations, followed by geometry optimization and energy calculation based on the first-principle planewave norm conserving pseudo-potential method of the density functional theory. Calculation results showed that under the condition of nonspin the doping concentration of W becomes heavier, the formation energy becomes greater, and doping becomes more difficult. Meanwhile, the total energy increases, the covalent weakens and ionic bonds strengthens, the stability of the W-doped anatase TiO2 decreases, the band gap increases, and the blue-shift becomes more significant with the increase of W doping concentration. However, under the condition of spin, after the band gap correction by the GGA+U method, it is found that the semimetal diluted magnetic semiconductors can be formed by heavy W-doped anatase TiO2. Especially, a conduction electron polarizability of as high as near 100% has been found for the first time in high concentration W-doped anatase TiO2. It will be able to be a promising new type of dilute magnetic semiconductor. And the heavy W-doped anatase TiO2 make the band gap becomes narrower and absorption spectrum red-shift.
authors.affiliation: College of Science, Inner Mongolia University of Technology, Hohhot, China.
authors.forename: Qingyu
authors.initials: Q
authors.lastname: Hou
authors.affiliation: College of Science, Inner Mongolia University of Technology, Hohhot, China; College of Arts and Sciences, Shanghai Maritime University, Shanghai, China.
authors.forename: Chunwang
authors.initials: C
authors.lastname: Zhao
authors.affiliation: College of Science, Inner Mongolia University of Technology, Hohhot, China.
authors.forename: Shaoqiang
authors.initials: S
authors.lastname: Guo
authors.affiliation: College of Science, Inner Mongolia University of Technology, Hohhot, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Mao
authors.affiliation: School of Material Science and Engineering, Beihang University, Beijing, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D002384:Catalysis; D004583:Electrons; D008027:Light; D059346:Magnets / Q000737:chemistry; D008958:Models, Molecular; D055668:Photochemical Processes; D011789:Quantum Theory; D013053:Spectrophotometry; D014025:Titanium / Q000737:chemistry*; D014414:Tungsten / Q000737:chemistry*
chemical_list: C009495:titanium dioxide; D014025:Titanium; D014414:Tungsten