• M AMLOUK

Articles written in Bulletin of Materials Science

• Effect of europium content on physical properties of In$_2$O$_3$ thin films for sensitivity and optoelectronic applications

In$_2$O$_3$:Eu thin films were successfully grown by spray pyrolysis. XRD studies showed that the films had In$_2$O$_3$ cubic structure with (004) preferential orientation and best crystal properties at 1.5% Eu doping level. Theoptical band gap energy decreased with Eu content around 4.1 eV. Urbach energy was of the order of 278 meV, it decreased with Eu content which indicates a decrease in the defects by doping. The dispersion of the refractive index was discussed. Raman spectroscopy showed the band positions corresponding to In$_2$O$_3$ cubic phase with a small shift related to europium incorporation within In$_2$O$_3$ matrix. PL measurements showed a large band which was located at 410 nm and related to the band-to-band transitions and other bands related to impurity levels. Finally, theelectric conductivity was investigated depending on the effect of temperature. Activation energy was found to range from 45 to 60 meV for films which were prepared with 1%Eu content.

• Structural, dielectric and a.c. conductivity study of Sb$_2$O$_3$ thin film obtained by thermal oxidation of Sb$_2$S$_3$

This work highlights some physical properties of Sb$_2$O$_3$ thin films obtained through heat treatment of Sb$_2$S$_3$ thin films under an atmospheric pressure at 400$^{\circ}$C. The obtained material is characterized by X-ray diffraction and impedance spectroscopy. X-ray diffraction analysis shows that Sb$_2$O$_3$ thin films were crystallized in cubic structure having a preferential growth along (222) plane. The grain size is found to be around 65 nm. The electrical conductivity was studied using impedance spectroscopy technique in the frequency range from 5 Hz to 13 MHz at temperatures lying in 638–698 K domain. Besides, the frequency and temperature dependence of the complex impedance, a.c. conductivity and complex electric modulus have been investigated.

• Simple route deposition and some physical investigations on nanoflower NiMoO$_4$ sprayed thin films

Nickel molybdate (NiMoO$_4$) thin film has been prepared by the spray pyrolysis method, using nickel chloride hexahydrate (NiCl$_2$.6H$_2$O) and ammonium molybdate tetrahydrate [(NH$_4$) 6Mo$_7$O$_{24}$.4H$_2$O] as precursors in the aqueous starting solution. First, the structure and the surface morphology characterizations were carried out by scanning electron spectroscopy (SEM), Raman and X-ray diffraction (XRD) techniques. Structural analysis by using XRD technique shows that the NiMoO$_4$ thin film crystallizes in the monoclinic phase, mainly orientation along (110), (021), ($\bar{2}04$), (220), (150) and ($\bar{1}52$), directions. In addition to these studies, the stoichiometric composition has been reached by the energy dispersion analysis technique. Second, the optical properties have been studied by means of the reflectance and the transmittance spectra, in the wavelength range of 300–1800 nm. This study shows a direct transition of this ternary oxide with an optical bandgap about 3.12 eV and Urbach energy $E_U$ in the order of 663 meV. Finally, the photoluminescence emission spectrum of the NiMoO$_4$ thin film showed emissions peaks in the violet and blue regions and others emission related to some defects in the prepared film.

• # Bulletin of Materials Science

Volume 45, 2022
All articles
Continuous Article Publishing mode

• # Dr Shanti Swarup Bhatnagar for Science and Technology

Posted on October 12, 2020

Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020