Molybdenum sulphide (MoS x ) particles were prepared from Na 2 MoO 4 and CH 3 CSNH 2 by the quick homogenous precipitation method within 5 min in alcohol-water solution at 82uC and normal pressure. The prepared MoS x particles were studied by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM). The results showed that the as prepared product was ball-like amorphous MoS x (x53 . 20) nanoparticles. The resultant amorphous ball-like MoS x nanoparticles were then calcined under hydrogen flow at a selected temperature for 50 min. The results of XRD, TEM and HRTEM confirmed that the ball-like MoS 2 nanoparticles with fullerene structure were prepared by calcining the amorphous MoS x nanoparticles at 780uC. The resultant ball-like nano-MoS 2 particles were transformed into polyhedron like nano-MoS 2 particles as the calcining temperature was increased to 960uC.
Ni particles supported on carbon nanotubes (CNTs) were dispersed in a polymethyl methacrylate (PMMA) matrix by solution blending and then cast onto an electrode to get composite films under low magnetic fields. The orientation of CNTs in the films was characterised by scanning electron microscope and optical microscope. Multimeter and high resistance meter were used to study the electrical behaviour of the nanocomposites. The glass transition temperature T g of PMMA was determined by differential scanning calorimetry. The results show that the alignment of the CNTs dispersed in the PMMA was achieved under a low magnetic strength below 0?5 T. Because of the ferromagnetism of Ni particles, the magnetic alignment of CNTs susceptibly changed. The magnetic alignment units in this work were rod-like CNTs aggregates instead of single CNTs, which took part in the buildup of a specific CNTs network structure in PMMA matrix. The network structure played a key role in significantly improving electrical conductivity and T g of the nanocomposites.
The electrical properties of a ceramic varistor depend strongly on its microstructural uniformity. In the present study, the microstructure of the Bi 2 O 3 -doped ZnO after sintering is characterized. A very small amount, 0.04 mol%, of Bi 2 O 3 -addition may induce density inhomogeneity in the early stage of sintering. A critical amount, >0.09 mol%, of Bi 2 O 3 is needed to result in density uniformity. The addition of Bi 2 O 3 can enhance the coarsening rate of ZnO grains; nevertheless, the grain size distribution is not affected.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.