Iranian Journal of Materials Science and Engineering

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Temperature is one of the key factor that affecting the electrical, physical, structural, and morphological properties as well as the crystallinity of the nanomaterials. The current study investigates the effect of annealing temperature on the structural and electrical properties of lanthanum oxide (La2O3) thick films. La2O3 thick films were prepared on a glass substrate using a conventional screen printing technique. In this work, T1 is an unannealed prepared film, whereas T2 and T3 are annealed in a muffle furnace for 3 hours at 350°C and 450°C, respectively. XRD technique was exploited to investigate the crystallization behavior of the films. It was found that the crystal structure of La2O3 thick films are pure hexagonal phase. The annealing temperatures were revealed to have influence on the crystallite sizes of the films. SEM and EDS was used to study the morphology and elemental analysis of the films respectively. The electrical properties of the films were explored by measuring resistivity, temperature coefficient of resistivity (TCR), and activation energy at lower and higher temperatures regions. The film annealed at 450°C has high resistivity, a high TCR, and small crystallite size. The thickness of the La2O3 thick films was also found to decrease as the annealing temperature increased.

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Nowadays metal oxide nanoparticles and transition metal dichalcogenides play a vital role in various areas like optical sensors, solar cells, energy storage devices, gas sensors and biomedical applications. In the current research work, we synthesized ZrSe₂ nanoparticles by hydrothermal method. The ZrSe₂ nanoparticles were synthesis using precursors such as ZrOCl₂.8H₂O and Na₂SeO₃.5H₂O in the addition of surfactant cetyl trimethyl ammonia bromide CTAB and reductant hydrazine hydrate, respectively. By using synthesized ZrSe₂ nanopowder thick films were developed on a glass substrate
using the screen printing method. The structural properties of ZrSe₂ powder were studied by X-ray diffraction (XRD). The X-ray diffraction analysis revealed that the hexagonal crystal structure and crystalline size were found to be 55.75 nm. The thick films of ZrSe₂ were characterized by field emission scanning electron microscopy (FESEM) and energy dispersive X-ray analysis (EDAX). The surface morphological analysis of ZrSe₂ nanostructured thick film shows hierarchical nanoparticles. The energy band gap of synthesized powder was calculated using a Tauc plot from UV-visible spectroscopy. The gas-sensing properties of ZrSe₂ thick films were studied. The developed ZrSe₂ thick films show maximum sensitivity and selectivity towards the ammonia NH₃ gas at an operating temperature of 120 °C and the gas concentration was 500 ppm. The developed thick films show fast response and recovery time.Nowadays metal oxide nanoparticles and transition metal dichalcogenides play a vital role in various areas like optical sensors, solar cells, energy storage devices, gas sensors and biomedical applications. In the current research work, we synthesized ZrSe₂ nanoparticles by hydrothermal method. The ZrSe₂ nanoparticles were synthesis using precursors such as ZrOCl₂.8H₂O and Na₂SeO₃.5H₂O in the addition of surfactant cetyl trimethyl ammonia bromide CTAB and reductant hydrazine hydrate, respectively. By using synthesized ZrSe₂ nanopowder thick films were developed on a glass substrate
using the screen printing method. The structural properties of ZrSe₂ powder were studied by X-ray diffraction (XRD). The X-ray diffraction analysis revealed that the hexagonal crystal structure and crystalline size were found to be 55.75 nm. The thick films of ZrSe₂ were characterized by field emission scanning electron microscopy (FESEM) and energy dispersive X-ray analysis (EDAX). The surface morphological analysis of ZrSe₂ nanostructured thick film shows hierarchical nanoparticles. The energy band gap of synthesized powder was calculated using a Tauc plot from UV-visible spectroscopy. The gas-sensing properties of ZrSe₂ thick films were studied. The developed ZrSe₂ thick films show maximum sensitivity and selectivity towards the ammonia NH₃ gas at an operating temperature of 120 °C and the gas concentration was 500 ppm. The developed thick films show fast response and recovery time.