arXiv subjects

Chhanda Basu Chaudhuri

Publications and source records attributed to Chhanda Basu Chaudhuri.

4 recordsLinked to original sources

arXiv2019

Increased metallicity of Carbon nanotubes because of incorporation of extended Stone-Wales' defects: an ab-initio real space approach

We propose an ab-initio combination of the Linear Muffin-Tin Orbital and the Recursion Methods to study the effect of extended Stone-Wales defects in single layer Carbon nanotubes. We have successfully applied this to zigzag and armchair tubes. The methodology involves no intrinsic mean-field like assumptions or external parameter fitting. As defects proliferate, the low density of states near the Fermi levels of the pristine tubes is filled with defect states. The increase of DOS at the Fermi level leads to enhanced conduction, which indicates enhanced metallicity due to SW defects in the nanotubes.

cond-mat.mes-hall↗

arXiv2019

Electronic and optical properties of Germagraphene, a direct band-gap semiconductor

In this communication, we report a theoretical attempt to understand the electronic and optical properties of germagraphene, a two-dimensional graphene analogue. We study two different structures, C$_{17}$Ge and C$_{16}$Ge. In the C$_{17}$Ge structure, a germanium atom replaces a carbon atom while in C$_{16}$Ge structure, a carbon-carbon bond is replaced by a single germanium atom. These two types of doping have been experimentally made possible by Tripathi \etal [{\it{ACS Nano (2018) 1254641-4647}}]. We find that C$_{16}$Ge has a planar structure, whereas, the Ge atom in C$_{17}$Ge settles in an out-of-the plane position, resulting in a buckled structure. Due to Ge doping, the band-gaps open up in both. The 1.227 eV direct gap of C$_{17}$Ge is ideal for effective light absorbance and optoelectronic devices. Further study of optical properties supports this claim as well.

physics.comp-ph↗

arXiv2000

Electronic structure and magnetism in disordered bcc Fe alloys

We here study electronic structure and magnetic properties of bcc Co$_{x}$Fe$_{1-x}$, Cr$_{x}$Fe$_{1-x}$ and Mn$_{x}$Fe$_{1-x}$ in their ferromagnetic phases using Augmented Space Recursion technique coupled with tight-binding linearized muffin tin orbital (TB-LMTO) method. We make a systematic study of magnetic properties like magnetic moment and Curie temperature and try to draw some conclusions on their variation across the row of 3-{\it d} transition metal series in periodic table using arguments based on effects like charge transfer, exchange splitting and hybridization.

cond-mat.mtrl-sci↗

arXiv2000

Effect of short range order on electronic and magnetic properties of disordered Co based alloys

We here study electronic structure and magnetic properties of disordered CoPd and CoPt alloys using Augmented Space Recursion technique coupled with the tight-binding linearized muffin tin orbital (TB-LMTO) method. Effect of short range ordering present in disordered phase of alloys on electronic and magnetic properties has been discussed. We present results for magnetic moments, Curie temperatures and electronic band energies with varying degrees of short range order for different concentrations of Co and try to understand and compare the magnetic properties and ordering phenomena in these systems.

cond-mat.mtrl-sci↗