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Wanwilai Chaisan Rattikorn Yimnirun David P. Cann 《Journal of solid state chemistry》2005,178(3):613-620
The electrical properties of ceramics within the TiO2-SnO2 system which exhibit spinodal decomposition were investigated under different annealing conditions. Changes in the lattice parameter and the phase evolution of the spinodal decomposition, measured in terms of the volume fraction transformed X(t), were examined as a function of annealing time using X-ray diffraction. The room temperature dielectric properties were measured and compared to dielectric mixing rules. Doping with pentavalent Nb was found to slow the decomposition kinetics and a high permittivity (εr>1000) was induced. The origin of the high permittivity is linked to the formation of an electrically heterogeneous structure which is derived from the spinodal microstructure. Lastly, it was observed that Nb-doped TiO2-SnO2 ceramics exhibited non-linear current-voltage behavior which can be attributed to the negative temperature coefficient of resistance effect. 相似文献
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Nattawadee Chaisan Wilailak Kaewsri Charnsak Thongsornkleeb Jumreang Tummatorn Somsak Ruchirawat 《Tetrahedron letters》2018,59(7):675-680
An efficient synthesis of N-acetyl-2-substituted indole derivatives via direct intramolecular hydroamination of N-acetyl-2-alkynylaniline derivatives was developed. The reaction could be applied to a wide range of substrates employing only 1–2?mol% of PtCl4 as the catalyst to furnish the desired indole products in moderate to excellent yields. The current protocol is efficient, reliable and scalable, and could serve as an important tool for convenient and rapid access to this important class of N-heterocyclic skeleton from readily available substrates. 相似文献
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