131 research outputs found

    Effect of Substrate Temperature on Structural and Optical Properties of Nanocrystalline CdTe Thin Films Deposited by Electron Beam Evaporation

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    Nanocrystalline Cadmium Telluride (CdTe) thin films were deposited onto glass substrates using electron beam evaporation technique. The effect of substrate temperature on the structural, morphological and optical properties of CdTe thin films has been investigated. All the CdTe films exhibited zinc blende structure with (111) preferential orientation. The crystallite size of the films increased from 35 nm to 116 nm with the increase of substrate temperature and the band gap of the films decreased from 2.87 eV to 2.05 eV with the increase of the crystallite size. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3195

    Effect of Annealing on Structural and Optical Properties of Cu Doped In2O3 Thin Films

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    Cu-doped In2O3 thin films were prepared using flash evaporation method at different Cu-doping levels. The effect of annealing was studied on the structure, morphology and optical properties of the thin films. The films exhibited cubic structure and optical transmittance of the films increasing with annealing temperature. The highest optical transmittance of 78 % was observed with band gap of 4.09 eV. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3553

    Capacidad antioxidante de cremas para galletas tipo sándwich con valor agregado a base de oleína roja de palma durante el almacenamiento

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    Red palm olein (RPOL) is naturally rich in antioxidants, yet changes in its antioxidant capacity during storage were uncertain, which limited the application of RPOL in fat-based food products. Therefore, this study incorporated shortenings composed of 0, 5, and 10% (w/w) RPOL into sandwich cookie creams of SCC-0, SCC-5, and SCC-10, respectively, and determined their antioxidant capacity during storage for six months at 20, 30, and 35 ºC. Both SCC-5 and SCC-10 exhibited higher carotene, tocopherol, tocotrienol, and total phenolic content (TPC) than that of SCC-0, yet all SCCs were comparable in their free fatty acid (FFA) and UV-total oxidation values. After six months, the SCCs exhibited low TPC and FFA, yet were high in DPPH scavenging activity. At 20 and 30 ºC, both SCC-5 and SCC-10 oxidized more slowly than that of SCC-0. These findings proved the antioxidant capacity of RPOL, which delayed oxidation reactions in the SCCs during storage.La oleína roja de palma (RPOL) es naturalmente rica en antioxidantes, pero los cambios en la capacidad antioxidante durante el almacenamiento no estaban claros y limitaron la aplicación de RPOL en productos alimenticios a base de grasas. En este estudio se incorporó mantecas compuestas por 0, 5 y 10 % (p/p) de RPOL en las cremas de galletas tipo sándwich (SCC): SCC-0, SCC-5 y SCC-10, respectivamente, y se determinó su capacidad antioxidante durante el almacenamiento durante seis meses a 20, 30 y 35 ºC. Tanto SCC-5 como SCC-10 exhibieron un mayor contenido de caroteno, tocoferol, tocotrienol y fenoles totales (TPC) que SCC-0, sin embargo, todas las SCC fueron comparables en sus valores de oxidación total de ácidos grasos libres (FFA) y UV. Después de seis meses, las SCC exhibieron TPC y FFA más bajos, pero fueron más altos en la actividad de eliminación de DPPH. A 20 y 30 ºC, tanto SCC-5 como SCC-10 se oxidaron más lentamente que SCC-0. Estos hallazgos demostraron la capacidad antioxidante de RPOL que retrasó las reacciones de oxidación en las SCC durante el almacenamiento

    Structural, Optical and Magnetic Properties of (In0.90Sn0.05Cu0.05)(2)O-3 Nanoparticles

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    This study examined structural, optical and magnetic properties of ITO (In0.95Sn0.05)(2)O-3 and Cu doped ITO (In0.90Sn0.05Cu0.05)(2)O-3 nanoparticles synthesized by solid state reaction method. The synthesized nanoparticles were subjected to structural, optical and magnetic studies. The structural properties of the nanoparticles were carried out using XRD, Raman, FT-IR characterization techniques. Optical properties of the samples were studies using UV-Vis-NIR spectrophotometer. The magnetic measurements were carried out using vibrating sample magnetometer. The ITO (In0.95Sn0.05)(2)O-3 nanoparticles exhibited room temperature ferromagnetism with clear hysteresis loop. The strength of magnetization decreased in Cu doped ITO (In0.95Sn0.05)(2)O-3. The ITO nanoparticles were also exhibited ferromagnetism at 100 K with a magnetic moment of 0.02 emu/g

    Structural, Optical, and Magnetic Properties of Co Doped CdTe Alloy Powders Prepared by Solid-State Reaction Method

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    Co doped CdTe powder samples were prepared by solid-state reaction method. In the present work effect of Co doping on structural, optical, and magnetic properties has been studied. X-ray diffraction studies confirm zinc blend structure for all the samples. The lattice parameter showed linear increase with the increase in Co content. The elemental constituents were characterized by EDAX. Optical studies showed the increase in band gap with increase in Co level. The samples were diluted magnetic semiconductors and exhibited clear hysteresis loop showing room temperature ferromagnetism as confirmed by vibrating sample magnetometer

    Effect of composition on the structure of lithium- and manganese-rich transition metal oxides

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    The choice of chemical composition of lithium- and manganese-rich transition metal oxides used as cathode materials in lithium-ion batteries can significantly impact their long-term viability as storage solutions for clean energy automotive applications. Their structure has been widely debated: conflicting conclusions drawn from individual studies often considering different compositions have made it challenging to reach a consensus and inform future research. Here, complementary electron microscopy techniques over a wide range of length scales reveal the effect of lithium-to-transition metal-ratio on the surface and bulk structure of these materials. We found that decreasing the lithium-to-transition metal-ratio resulted in a significant change in terms of order and atomic-level local composition in the bulk of these cathode materials. However, throughout the composition range studied, the materials consisted solely of a monoclinic phase, with lower lithium content materials showing more chemical ordering defects. In contrast, the spinel-structured surface present on specific crystallographic facets exhibited no noticeable structural change when varying the ratio of lithium to transition metal. The structural observations from this study warrant a reexamination of commonly assumed models linking poor electrochemical performance with bulk and surface structure
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