Ultraviolet Region Of Electromagnetic Spectrum Research Articles

DFT Investigations of Structural, Magnetic, Electronic, and Optical Properties of CsEuCl3

Full potential linearized augmented plane wave method was used to calculate structural, electronic, magnetic, and optical properties of CsEuCl3 within the framework of density functional theory. The ground state stability of CsEuCl3 was tested among non-magnetic, ferromagnetic, and anti-ferromagnetic phases. It was found that CsEuCl3 is stable in ferromagnetic phase. The computed ground state structural parameters in stability phase show excellent agreement with the available literature. The spin-polarized electronic properties reveal that CsEuCl3 is a direct band gap semiconductor in spin-up channel and large indirect band semiconductor in spin-down states. So, the overall nature of CsEuCl3 is semiconductor. The computed magnetic properties show that the main contribution toward ferromagnetic nature of studied compound is from the Eu atom. The calculated optical properties indicated the usefulness of CsEuCl3 in devices working in visible and ultraviolet regions of electromagnetic spectrum.

Preparation and spectroscopic analysis of zinc oxide nanorod thin films of different thicknesses

AbstractZinc oxide thin films with different thicknesses were prepared on microscopic glass slides by sol-gel spin coating method, then hydrothermal process was applied to produce zinc oxide nanorod arrays. The nanorod thin films were characterized by various spectroscopic methods of analysis. From the images of field emission scanning electron microscope (FESEM), it was observed that for the film thickness up to 200 nm the formed nanorods with wurtzite hexagonal structure were uniformly distributed over the entire surface substrate. From X-ray diffraction analysis it was revealed that the thin films had good polycrystalline nature with highly preferred c-axis orientation along (0 0 2) plane. The optical characterization done by UV-Vis spectrometer showed that all the films had high transparency of 83 % to 96 % in the visible region and sharp cut off at ultraviolet region of electromagnetic spectrum. The band gap of the films decreased as their thickness increased. Energy dispersive X-ray spectroscopy (EDS) showed the presence of zinc and oxygen elements in the films and Fourier transform infrared spectroscopy (FT-IR) revealed the chemical composition of ZnO in the film.

Ab initiocalculations of transition amplitudes and hyperfineAandBconstants of Ga iii

In this paper, the $E1$, $E2$, and $M1$ transition amplitudes are calculated along with the hyperfine $A$ and $B$ constants of doubly ionized gallium using the relativistic coupled-cluster approach. Electron correlations and the Gaunt interactions are considered to all orders using the coupled-cluster theory in a relativistic framework and their contributions are discussed explicitly in the calculations of all these amplitudes. Some interesting features of the correlation effects on the Gaunt interactions are noticed in the calculations of the hyperfine constants. The lifetimes of some low-lying states are also calculated using the transition amplitudes obtained by the present theory and the experimental transition energies. The calculated $E1$ transition amplitudes and lifetimes are in good agreement with the results obtained by the other theories and experiment. The hyperfine splitting of the ground states of ${}^{71}$Ga iii and ${}^{69}$Ga iii are found to be about 35 and 27.5 GHz, respectively, which shows the importance of these isotopes for the possible use of microwave frequency standards. The calculated hyperfine constants are associated with linewidth estimations of some transition lines in the visible and ultraviolet regions of electromagnetic spectrum.