We investigate the effects of nitrogen impurities on the electronic properties of quantum dots realized in Z-shaped graphene nanoribbon junction. The system is studied using first principle calculations, based on the local spin density approximation (LSDA). Our results indicate that the presence of the impurities drastically changes the configuration of the localized states in the quantum dot. ...

The local-spin-density approximation and the generalized-gradient approximation ~GGA! are used to perform density-functional total-energy calculations at zero temperature for Fe3Al in the ordered D03 and L12 structures. Our calculations show that commonly used GGA functionals fail to predict the experimentally stable D03 structure as the one with the lower total energy. This qualitative discrep...

This work assesses the Heyd-Scuseria-Ernzerhof HSE screened Coulomb hybrid density functional for the prediction of lattice constants and band gaps using a set of 40 simple and binary semiconductors. An extensive analysis of both basis set and relativistic effects is given. Results are compared with established pure density functionals. For lattice constants, HSE outperforms local spin-density ...

New computational technique based on linear-scale differential analysis (LSDA) of digital image is proposed to find the best focus position in digital microscopy by means of defocus estimation in two near-focal positions only. The method is based on the calculation of local gradients of the image on different scales using its convolution with a number of differential filters of linearly varying...

Submitted for the MAR09 Meeting of The American Physical Society Proposed Orbital Ordering in MnV2O4 from First-principles Calculations1 TANUSRI SAHA-DASGUPTA, SOUMYAJIT SARKAR, S.N.Bose National Centre for Basic Sciences, TULIKA MAITRA, Department of Physics, Indian Institute of Technology, Roorkee, India, ROSER VALENTI, Institut für Theoretische Physik, J. W. Goethe Universität, Frankfurt, Ge...

We have investigated the role of transition metal impurities and oxygen vacancies in the formation of ferromagnetism in Co-doped TiO2 using LSDA+U approach which takes into account strong on-cite Coulomb correlations for electronic structure calculations. Several model systems such as supercells of rutile TiO2 with Co ion in high-spin state substituted into titanium cite and with oxygen vacanci...

Resonant photoemission of single crystals of the double perovskites GdBaCo2O5+d and DyBaCo2O5+d has been carried out at the UK Synchrotron Radiation Source at Daresbury. The resonance onset energy at the Co 3p→3d threshold is used to explore the Co spin state in the double perovskites as a function of temperature. In contrast with the simple perovskites LaCoO3 and HoCoO3, an undelayed resonance...

Charge transfer between metal ions occupying distinct crystallographic sublattices in an ordered material is a strategy to confer visible light absorption on complex oxides to generate potentially catalytically active electron and hole charge carriers. CaCu3Ti4O12 has distinct octahedral Ti4+ and square planar Cu2+ sites and is thus a candidate material for this approach. The sol−gel synthesis ...

Fatty liver disease (FLD) is reversible disease and can be treated, if it is identified at an early stage. However, if diagnosed at the later stage, it can progress to an advanced liver disease such as cirrhosis which may ultimately lead to death. Therefore, it is essential to detect it at an early stage before the disease progresses to an irreversible stage. Several non-invasive computer-aided...