Publications by authors named "Tulika Maitra"

Article Synopsis
  • The study synthesizes nanocrystalline samples of NixFe1-xCo2O4 at varying nickel concentrations via co-precipitation and annealing at 900 °C, revealing different crystallization phases and decreased particle size with more nickel substitution.
  • Magnetic properties were analyzed, showing metamagnetic transitions in certain samples and dynamic susceptibility dependent on both nickel content and temperature, indicating complex magnetic states like spin-glass freezing.
  • First principles density functional theory calculates suggest these materials exhibit ferrimagnetic and insulating behaviors, with potential applications in spintronics due to their distinctive electronic structures and spin-dependent characteristics.
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Spintronics is an emerging form of electronics based on the electrons' spin degree of freedom for which materials with robust half-metallic ferromagnet character are very attractive. Here we determine the structural stability, electronic, magnetic, and mechanical properties of the half-Heusler (hH) compound CoFeGe, in particular also in its cubic form. The first-principles calculations suggest that the electronic structure is robust with 100% spin polarization at the Fermi level under hydrostatic pressure and uni-axial strain.

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A new multisensor (i.e. resistive and magnetic) CrI-WTe heterostructure (HS) to detect the toxic gases BrF and COCl (Phosgene) has been theoretically studied in our present investigation.

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The electronic structure of double perovskite PrMnNiO was studied using core x-ray photoelectron spectroscopy and x-ray absorption spectroscopy. The 2p x-ray absorption spectra show that Mn and Ni are in 4+  and 2+  states respectively. Based on charge transfer multiplet analysis of the 2p XPS spectra of both ions, we find charge transfer energies [Formula: see text] of 3.

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Our first principles density functional theory calculations within GGA + U approximation reveal that the nature of transport gaps in the zircon and scheelite phases of DyCrO(4) are quite different. While in the scheelite phase the origin of the gap is more like that of the Mott-Hubbard systems, in the zircon phase the origin is not strictly a Mott-Hubbard or a charge transfer type. In the framework of the Zaanen-Sawatsky-Allen phase diagram, the DyCrO(4) in its zircon phase could be placed in the intermediate regime between the charge transfer and Mott-Hubbard insulators.

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Inspired by recent experiments, we have theoretically explored the nature of itineracy in CoV2O4 under pressure and investigated, using first-principles density functional theory calculations, whether it has any magnetic and orbital ordering. Our calculations indicate that there could be two possible routes for obtaining the experimentally observed pressure induced metallicity in this system. One is via the spin–orbit interaction coupled with Coulomb correlation, which can take the system from a semiconducting state at ambient pressure to a metallic state under high pressure.

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Recent measurements on MgV(2)O(4) single crystals have reignited the debate on the role of spin-orbit (SO) coupling in dictating the orbital order in vanadium spinel systems. Density functional theory calculations were performed using the full-potential linearized augmented-plane-wave method within the local spin density approximation (LSDA), Coulomb correlated LSDA (i.e.

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In view of recent controversy regarding the orbital order in the frustrated spinel ZnV(2)O(4), we analyze the orbital and magnetic ground state of this system within an ab initio density functional theory approach. While local density approximation+Hubbard U calculations in the presence of a cooperative Jahn-Teller distortion stabilize an A-type staggered orbital order, the consideration of relativistic spin-orbit (SO) effects unquenches the orbital moment and leads to a uniform orbital order with a net magnetic moment close to the experimental one. Our results show that ab initio calculations are able to resolve the existing discrepancies in previous theories and that it is the SO coupling along with electronic correlations which play a significant role in determining the orbital structure in these materials.

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