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Huang S.,Key Laboratory of Materials Modification by Laser | Xu Q.,Kyoto University | Yoshiiie T.,Kyoto University
Materials Letters

The effects of Cr and W solute atoms on the evolution of irradiation-induced defects in Fe-8Cr and Fe-8Cr-2W alloys upon annealing after low-temperature neutron and electron irradiation were investigated by using positron annihilation lifetime measurements. Vacancy defects behavior at elevated temperatures showed that added solute Cr and W in Fe clearly suppress void growth. The void swelling suppression by Cr was explained using configuration-trapping model. For the W solute effects, the results of two types of irradiation support the solute and dislocation interaction model. Related results are important for the fabrication of improved radiation-resistant materials for fission or fusion reactors. © 2016 Elsevier B.V. Source

Han Y.,Nanjing University | Ge G.-X.,Nanjing University | Wan J.-G.,Nanjing University | Zhao J.-J.,Key Laboratory of Materials Modification by Laser | And 2 more authors.
Physical Review B - Condensed Matter and Materials Physics

We predict that a combined system of Ir dimer situated on the single-vacancy (SV) graphene is extremely stable and has high magnetic anisotropy energy (MAE), promising to be a potential candidate for high density magnetic storage. Our theoretical results show that high energy gradient in the SV graphene makes it possible to move the Ir dimer from the perfect graphene area into the center of SV (CSV), leading to the formation of the highly stable system with the Ir-Ir bond axis exactly perpendicular to the graphene plane. The calculated MAE value is as large as 25.7 meV per Ir atom. The origin of giant MAE in such a system is attributed to the difference of local densities of electronic states magnetized along different directions caused by special symmetry of Ir2 at CSV. We also propose a feasible avenue to assemble the Ir dimers on the graphene with the pattern of SV defects for actual applications. © 2013 American Physical Society. Source

Cao S.P.,Dalian University of Technology | Ye F.,Dalian University of Technology | Ye F.,Key Laboratory of Materials Modification by Laser | Hou B.,Dalian University of Technology | Xu A.Y.,Dalian University of Technology
Thin Solid Films

Aluminum-doped zinc oxide films were prepared using electron beam evaporation method at a series of oblique angles.It has been found out that the columnar structure in the films inclined with oblique angle.Moreover, the angle between the growth direction of the columnar structure and the substrate normal was essentially the same as the oblique angle.The film thickness, the average transmittance, the normalized absorption and the sheet resistance also varied as a function of angle.These properties also gradually varied along the film's surface.Then, the effects of oblique angle deposition on the film properties were discussed based on deposition speed and shadowing effect.© 2013 Elsevier B.V.All rights reserved. Source

Du Y.,University of Wollongong | Zhuang J.,University of Wollongong | Liu H.,Key Laboratory of Materials Modification by Laser | Xu X.,University of Wollongong | And 9 more authors.
ACS Nano

Silicene monolayers grown on Ag(111) surfaces demonstrate a band gap that is tunable by oxygen adatoms from semimetallic to semiconducting type. With the use of low-temperature scanning tunneling microscopy, we find that the adsorption configurations and amounts of oxygen adatoms on the silicene surface are critical for band gap engineering, which is dominated by different buckled structures in √13 × √13, 4 × 4, and 2√3 × 2√3 silicene layers. The Si-O-Si bonds are the most energy-favored species formed on √13 × √13, 4 × 4, and 2√3 × 2√3 structures under oxidation, which is verified by in situ Raman spectroscopy as well as first-principles calculations. The silicene monolayers retain their structures when fully covered by oxygen adatoms. Our work demonstrates the feasibility of tuning the band gap of silicene with oxygen adatoms, which, in turn, expands the base of available two-dimensional electronic materials for devices with properties that is hardly achieved with graphene oxide. © 2014 American Chemical Society. Source

Ma J.L.,Dalian University of Technology | Ye F.,Dalian University of Technology | Ye F.,Key Laboratory of Materials Modification by Laser | Ou D.R.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Journal of Physical Chemistry C

Defect clusters containing oxygen vacancies and Ce3+ cations on ceria (CeO2) surface dominate the electronic and chemical properties of the surface. However, the structures of the clusters, especially the arrangements of the oxygen vacancies in the clusters, have not been explained consistently. In this work, atomistic simulation based on energy minimization has been used to investigate the cluster structures on ceria {111} surface. It was found out that the oxygen vacancies are energetically favorable to be at the second-neighbor sites to their associated Ce3+ cations. Moreover, the subsurface oxygen vacancies on the third layer are essential for the arrangement of the surface oxygen vacancy clusters. Due to the existence of the subsurface oxygen vacancies, the adjacent surface oxygen vacancies tend to be separated by 〈110〉/2, and the linear surface clusters are more energetically favorable than the triangle ones. Then, the structure development with cluster size is discussed. © 2012 American Chemical Society. Source

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