The energetics of Ni vacancy jumps in the intermetallic compound NiAl are studied by combining embedded-atom and first-principles calculations. The embedded-atom potential used in this work is fit to both experimental and first-principles data and provides an accurate description of point defect energies and vacancy jump barriers in NiAl. Some of the embedded-atom results reported here, are ind...

We study from first principles the magnetism in graphene induced by single carbon atom defects. For two types of defects considered in our study, the hydrogen chemisorption defect and the vacancy defect, the itinerant magnetism due to the defect-induced extended states has been observed. Calculated magnetic moments are equal to 1 B per hydrogen chemisorption defect and 1.12–1.53 B per vacancy d...

Perturbed angular correlation of gamma rays (PAC) was applied to measure concentrations of point defects in quenched and milled intermetallic compounds. Two systems with high ordering energies were studied, PdIn and NiAl, with principal results obtained for PdIn. The defects, lattice vacancies and antisite atoms, were detected by quadrupole interactions induced at nuclei of nearby In/Cd probe a...

As part of a multi-scale approach for modeling hydrogen embrittlement in hardened steels we have investigated, employing density functional theory methods, the stability and concentrations of the point defect clusters present in metastable Fe-C-H alloys with vacancies. The defect spectrum is found to be strongly dependent on the local vacancy concentration, and for low hydrogen levels sharp hig...

The electronic behavior of metallic carbon nanotubes under the influence of atomistic vacancy defects present in the channel is theoretically investigated using non-equilibrium Green’s function method self-consistently coupled with three-dimensional electrostatics. A nearest neighbor tight binding model based on a single pz orbital is used for the device Hamiltonian. A single vacancy defect in ...

The density and spatial distribution of oxide precipitates within a crystalline silicon wafer is of paramount importance for microelectronic device yield. In this letter, the authors show how the formation of previously unconsidered, very small vacancy aggregates can explain macroscopic spatial variations in the oxide precipitate density, which are observed following certain rapid thermal annea...

We present calculations of the bound state energy levels of anion vacancies near the surface of a III-V semiconductor. We consider the (110) surface of GaAs, InP, and the Ga1_xAlxAs alloy system. As the vacancy is moved toward the surface, the energy levels are only slightly perturbed until the vacancy reaches the second atomic layer from the surface. At this point, the anion vacancy levels mov...

the cluster representation matrices have already been successfully used to enumerate close-packed vacancy clusters in all single-lattice crystals [i, 2]. point defect clusters in double-lattice crystals may have identical geometry but are distinct due to unique atomic postions enclosing them. the method of representation matrices is extended to make it applicable to represent and enumerate the ...

Rights: © 2010 American Physical Society (APS). This is the accepted version of the following article: Dong, Yufeng & Tuomisto, Filip & Svensson, B. G. & Kuznetsov, A. Yu. & Brillson, Leonard J. 2010. Vacancy defect and defect cluster energetics in ion-implanted ZnO. Physical Review B. Volume 81, Issue 8. 081201/1-4. ISSN 1098-0121 (printed). DOI: 10.1103/physrevb.81.081201, which has been publ...

Citation Kabir, Mukul et al. " Effects of vacancy-solute clusters on diffusivity in metastable Fe-C alloys. Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Diffusi...