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Here, we demonstrated a novel method to decorate Cu9S5 nanocrystals on polyaniline (PANI) nanowires using the dopant of mercaptoacetic acid (MAA) in the PANI matrix as the sulfur source under a hydrothermal reaction. TEM images showed that Cu9S5 nanocrystals with a size in the range of 5-20 nm were uniformly formed on the surface of PANI nanowires. Significantly, the as-prepared PANI/Cu9S5 composite nanowires have been proven to be novel peroxidase mimics toward the oxidation of the peroxidase substrate 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2. Due to the synergetic effects between polyaniline nanowires and Cu9S5 nanocrystals, the obtained PANI/Cu9S5 composite nanowires exhibit superior catalytic activity over the independent components. This work not only presents a simple and versatile method to decorate semiconductor nanocrystals on the surface of conducting polymer nanostructures, but also provides fundamental guidelines for further investigations into the synergetic effect between conducting polymers and other materials. [ABSTRACT FROM AUTHOR]

The microstructure and crystallography of 20MnCr5 steel tempered at 180 °C for 2 h were examined by electron back scattered diffraction (EBSD) in a field-emission scanning electron microscope. The crystallographic features of martensite in a prior austenite grain area were studied by pole figures (PFs). Compared to the theoretical PFs calculated with Kurdjumow–Sachs (K–S) and Nishiyama–Wassermann (N–W) orientation relationships (ORs), it is shown that both of the ORs exist in the investigated specimens. Misorientations distribution and the result of transmission electron microscope analysis indicating that [011]/54.7° lath boundary existed in the microstructure also prove the coexistence of K–S and N–W ORs. When the steels were further tempered at 350 °C/20 min or 500 °C/20 min, the length of boundaries in equal areas decreased and the crystallographic features still fulfill the coexistence of K–S and N–W ORs. [ABSTRACT FROM AUTHOR]

(Ba0.69Pb0.31)TiO3 ceramics were prepared using Al2O3, SiO2, additives and excess of TiO2 (AST). The characteristics of positive temperature coefficient of resistivity (PTCR) was studied and the corresponding microstructures were investigated using atomic force microscopy and scanning electron microscopy. The results showed that the PTCR effect was related to the AST additives. The maximum value of resistivity in the ceramics with lower content of or without Al2O3 and SiO2 additives was much lower than in those with AST additives. Ceramics with low AST content, which were heated by electric field to a temperature much higher than their Curie temperature, lost the PTCR effect after the electric field stimulation. The microstructure observations revealed that re-crystallization took place in the ceramics with lower content of or without AST additives resulting in the loss of the PTCR effect. [ABSTRACT FROM AUTHOR]

La-doped BaPbO3 ceramics were prepared by using BaCO3 and PbO. Electrical properties and microstructure of the ceramics were studied. The results show a thin surface layer with a very low resistivity, and the interior of the ceramics with the characteristics of positive temperature coefficient of resistivity (PTCR). The PTCR behavior was related to the La content. The investigation by scanning electron microscopy and transmission electron microscopy revealed that the low resistivity of the surface layer was due to formation of a nano-size BaPbO3 phase with metallic properties. [ABSTRACT FROM AUTHOR]