arXiv subjects

Satyananda Chabungbam

Publications and source records attributed to Satyananda Chabungbam.

3 recordsLinked to original sources

arXiv2017

CrCTe$_3$: Computational design of a robust two-dimensional anti-ferromagnetic semiconductor

Using density functional theory calculations we establish the hitherto unknown compound CrCTe$_3$ to be a stable anti-ferromagnetic semiconductor in the R$\bar{3}$ crystal structure with an indirect fundamental gap . Successive layers in the bulk compound are weakly bound by van der Waals forces so that individual layers can be easily exfoliated. A monolayer of CrCTe$_3$ is also an anti-ferromagnetic semiconductor. The monolayer is structurally stable over a large range of compressive and tensile strains, and the anti-ferromagnetic state is robust over this strain range. Band gap of the monolayer can be tuned by as much as 50% by applying strain in this range.

cond-mat.mtrl-sci↗

arXiv2015

Atomic level understanding of site-specific interactions in Polyaniline/TiO2 composite

The results of spin-polarized density functional theory calculations find that band gap engineering can be achieved by site-specific interactions in a composite consisting of polyaniline and TiO2 nanoparticles. Interactions in the composite matrix are found to be mediated by Ti atoms inducing dependency of location of the conduction band minimum on the polyaniline site which is being probed by TiO2. This dependency is due to subtle changes in the nature of valance or conduction states near Fermi level introduced by the interacting matrix sites. The results therefore suggest that optimization of the synthesis parameters at atomic level can be an effective way to improve performance of a photovoltaic device based on PAni- TiO2 composite.

cond-mat.mtrl-sci↗

arXiv2015

First principles correspondence of a second type of phonon anomaly along [211] to the Fermi nesting features and associated electron-phonon interactions in Ni$_2$FeGa

First principles calculation supports the occurence of a phonon anomaly along [211] in Ni$_2$FeGa that was observed experimentally for the first time as structural modulations along [211] direction. Fermi surface scans have been performed in both austenite and martensite phase to observe the possible Fermi nesting features in the system. The magnitude of observed Fermi surface nesting vectors in (211) plane exactly match the phonon anomaly wavevectors along [211] direction. Electron-phonon calculations in the austenite phase shows that there is significant electron-phonon coupling in the system which may arise out of the lattice coupling between lower acoustic phonon modes and higher optical phonon modes and also because of strong Fermi surface nesting features observed in the system.

cond-mat.mtrl-sci↗