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We report a novel top-down procedure to obtain CU2O nanoparticles in two steps. In the first step a chemical method is used to synthesis CU2O particles of ~500 nm in size. In the second step, these particles are fragmented into ~70 and ~10 nm sized Cu2O particles by using nanosecond (532 nm, 7 ns and 10 Hz) and picosecond (532 nm, 30 ps and 10 Hz) pulses, respectively. A comparative study based on laser pulse duration has shown the superiority of picosecond pulses over nanosecond pulses. [ABSTRACT FROM AUTHOR]

Lithium triniobate (LiNb3O8) has been prepared using microwave assisted combustion synthesis at a low temperature of 400 °C. Graphite oxide is synthesized using Hummers method and thereafter it is thermally exfoliated at 500 and 700 °C to obtain two samples of Few Layered Graphene (FLG). Then, FLG-LiNb3O8 composites prepared through a simple ultra-sonication assisted solution mixing process. The obtained samples are named as FLN5 and FLN7 based on the temperature used to obtain FLG. Low frequency dielectric measurements are recorded for both the samples and the measured dielectric constant is observed to be more for FLN5 (250 at 60 Hz) than FLN7 (115 at 60 Hz) whilst the dielectric loss is less in case of FLN5 (1.525 at 60 Hz). The enhancement in dielectric properties for FLN5 is explained in terms of polarization in FLG-LiNb3O8 composites. [ABSTRACT FROM AUTHOR]

Amongst various carbon nanomaterials, carbon nanofibers (CNFs) have lately attracted considerable interest as a promising reinforcement in polymer matrix composites. CNFs are often synthesized using copper nanoparticles as catalysts and by using chemical vapor deposition (CVD). In this work iron (Fe) nanoparticles are used as catalysts to synthesize amorphous carbon nanofibers. This owes significance since Fe nanoparticles often lead to tubes rather than fibers. Fe nanoparticles (size ∼30-60nm) are prepared by first mixing an appropriate quantity of potassium sodium tartrate tetrahydrate salt with iron (II) chloride dehydrate to obtain iron tartrate and then dried and heated in vacuum oven at about 250°C to remove tartrate. In a subsequent step, CNFs are obtained by using CVD. Acetylene was used as the carbon source in the CVD process. Scanning and transmission electron microscopy show the formation of nanofibers whose diameter is dependent on the size of Fe catalysts. Raman scattering from the fibers show that they are made up of carbon and are amorphous. [ABSTRACT FROM AUTHOR]

Lithium triniobate (LiNb3O8) has been prepared using microwave assisted combustion synthesis at a low temperature of 400 °C. Graphite oxide is synthesized using Hummers method and thereafter it is thermally exfoliated at 500 and 700 °C to obtain two samples of Few Layered Graphene (FLG). Then, FLG-LiNb3O8 composites prepared through a simple ultra-sonication assisted solution mixing process. The obtained samples are named as FLN5 and FLN7 based on the temperature used to obtain FLG. Low frequency dielectric measurements are recorded for both the samples and the measured dielectric constant is observed to be more for FLN5 (250 at 60 Hz) than FLN7 (115 at 60 Hz) whilst the dielectric loss is less in case of FLN5 (1.525 at 60 Hz). The enhancement in dielectric properties for FLN5 is explained in terms of polarization in FLG-LiNb3O8 composites. [ABSTRACT FROM AUTHOR]