We present calculations of the bound state energy levels of ideal vacancies near the ( 110) surface of some zinc blende II-VI and Ill-Y semiconductors: CdTe, ZnTe, GaAs, AlAs, InAs, and some alloys among them. Here we compare vacancies near the surface ofii-VI's with those ofiii-V's. In contrast to the III-V's, where a neutral vacancy has an odd number of electrons, a neutral vacancy in a II-VI...

We examine the effect of vacancies on the phase behavior and structure of systems consisting of hard cubes using event-driven molecular dynamics and Monte Carlo simulations. We find a first-order phase transition between a fluid and a simple cubic crystal phase that is stabilized by a surprisingly large number of vacancies, reaching a net vacancy concentration of approximately 6.4% near bulk co...

We have used the indium/copper surface alloy to study the dynamics of surface vacancies on the Cu(001) surface. Individual indium atoms that are embedded within the first layer of the crystal, are used as probes to detect the rapid diffusion of surface vacancies. STM measurements show that these indium atoms make multi-latticespacing jumps separated by long time intervals. Temperature dependent...

Study of permeability of Fibrous Composites is important in several natural and industrial processes in mechanical engineering. In this study, a comprehensive mathematical model is presented for calculation of normal permeability of ordered elliptical fibrous media. An innovative scale-analysis technique is employed for determining the normal permeability of elliptical fibrous media. In this te...

We perform first-principles density-functional theory calculations to investigate the structural and electronic properties and the formation energies of nitrogen vacancies in wurtzite InN. We report an extensive and systematic study of the favorable atomic and electronic configurations of up to six vacancies in large supercells. The isolated vacancy acts as a donor in a p-type material where th...

Oxygen vacancies have a profound effect on the magnetic, electronic, and transport properties of transition metal oxide materials. Here, we studied the influence of oxygen vacancies on the magnetoresistance (MR) properties of SrRu1 - x Fe x O3 - δ epitaxial thin films (x = 0.10, 0.20, and 0.30). For this purpose, we synthesized highly strained epitaxial SrRu1 - x Fe x O3 - δ thin films with ato...

Oxidation of alloy often involves chemical partition and injection of vacancies. Chemical partition is the consequence of selective oxidation, while injection of vacancies is associated with the differences of diffusivity of cations and anions. It is far from clear as how the injected vacancies behave during oxidation of metal. Using in-situ transmission electron microscopy, we captured unprece...

Detonation nanodiamond particles (DND) contain highly-stable nitrogen-vacancy (N-V) centers, making it important for quantum-optical and biotechnology applications. However, due to the small particle size, the N-V concentrations are believed to be intrinsically very low, spawning efforts to understand the formation of N-V centers and vacancies, and increase their concentration. Here we show tha...