RESUMEN
Unadulterated and scorch stage In2SnO3 nanopowder is effectively arranged with the doping proportion of 80-20% (In2O3-Sn) by simple sol-gel combustion direction. The material is characterized by XRD measurements and their geometrical parameters are compared with calculated values. The FT-IR and NMR spectra are recorded in both bulk and nanophase and FT-Raman spectrum is recorded in bulk phase and the fundamental frequencies are assigned. The optimized parameters and the frequencies are calculated using HF and DFT (B3LYP, B3PW91 and MPW1PW91) theory in bulk phase of In2SnO3 and are compared with its nanophase. The vibrational frequency pattern in nanophase gets realigned and the frequencies are shifted up and down little bit to the region of spectra when compared with bulk phase. The UV-visible spectrum is simulated and analyzed. The frontier molecular orbital analysis has been carried out and the values of the HOMO-LUMO bandgap (Kubo gap) explore the optical and electronic characteristics of the In2SnO3. Structural studies by XRD showed the crystallite sizes of the particles. The atomic arrangement in the grain boundary seems to be somewhat different from regular periodic arrangement whereas inside the grain there is a good periodic arrangement of atoms. Above 10 mol% Sn ions, 15 mol% Sn ions, 20 mol% Sn ions to 50 mol% Sn ions form correlated clusters, 20 mol% Sn ions which lead to broadening. These EPR spectra were formed to contain two different components, one from the single isolated ions and the other from the clusters. The transition is observed for different composition increase with decreasing grain size.
RESUMEN
Telluride's and Selenides were assessed whether it is appropriate for thermoelectric effects. Previous researches showed that researchers strived to progress the performance of telluride based materials in creating structures where the entire dimensions are reduced, such as nanowires or thin films. Seebeck and Peltier coefficient was developed by means of Telluride thermoelectric devices. Epitaxial growth methods such as molecular beam epitaxy and metal organic chemical vapor deposition are some of the frequent methods of acquiring telluride thin films. Thermoelectric nano thin films and nanostructured materials should have the properties of insulation so that it can be used as energy storage devices and thermo electric generators. Conduction of electricity is usually convoyed by reversible and irreversible effects, such as electrical resistance and thermal conduction which is used to, Peltier refrigerators, generating electricity, renewable energies and its applications. Telluride films can be used in thermoelectric applications; these thermoelectric materials are mainly rare metals such as (Bi), (Te), (Pb) and (Sb). Thermal conductivity, figure of merit is advantageous factor of these energy storage devices. Thermoelectric cooler, thermoelectric generators are the powerful sources which can be eligible due to the use of telluride thin films. The thermal conductivity performance, figure of merit and Seebeck and Peltier coefficients of diverse materials were conferred.
RESUMEN
Nanomaterials of CeO2 with A. vera were synthesized by using simple chemical method. Grapes drops are used as an oxidizing agent. Structural and morphological studies of nanomaterials of cerium oxide (CeO2), were studied for combustion method of preparation. The precursor solution was initialized by a hydrothermal reaction. Cerium hydroxyl carbonate precursors which involves cerium (III) nitrate Ce(NO3)3. 6 H2O with (1.0M) of seashell powder, 3% A. vera, extracts, grapes and pomegranate drops and this complex solution was used to produce the CeO2 powder particles. We have prepared another sample with 5% of Aloe vera extract and found that 3% Aloe vera extract has lesser grain size and enhanced band gap values, so the article explained the sample analysis of combination with 3% extract of Aloe vera. The product has the rod pattern which was the unusual features appear to originate from the unique crystal chemistry aspects. From the optical absorption spectrum, it has been shown that the CeO2 rods have 3.847eV of direct band gap energy. The minimum inhibitory concentration (MIC) values of the synthesized compounds exhibited activity towards various microbial pathogens such as B. subtilis (15µg/mL), S. aureus (50µg/mL), S. epidermidis (20µg/mL), E. faecalis (25µg/mL) and towards E. coli (100µg/mL), K. pneumoniae (50µg/mL) and P. aeruginosa (75µg/mL) respectively. The tests on bacterial activities confirmed that the CeO2 rods are suitable hand for the biological applications. The seashell structure and the phytochemical contents of A. vera might enhance its bacterial activities.