title: Nanocomposite dielectrics in PbO-BaO-Na2O-Nb2O5-SiO2 system with high breakdown strength for high voltage capacitor applications.
abstract: Nanocomposite dielectrics in 6PbO-4BaO-20Na2O-40Nb2O5-30SiO2 system were prepared via melt-quenching followed by controlled crystallization. X-ray diffraction studies reveal that Pb2Nb2O7, Ba,NaNb5O15, NaNbO3 and PbNb2O6 phases are formed from the as-quenched glass annealed in temperature range from 700 degrees C to 850 degrees C. Ba2NaNb5O15, Pb2Nb2O7 crystallizes at 700 degrees C and then Pb2Nb2O7 disappears at 850 degrees C, while PbNb2O6 and NaNbO3 are formed at 850 degrees C. Microstructural observation shows that the crystallized particles are nanometer-sized and randomly distributed with glass matrix being often found at grain boundaries. The dielectric constant of the nanocomposites formed at different crystallization temperatures shows good frequency and electric field stability. The breakdown strength is slightly decreased when the glass-ceramics thickness is varied from 1 mm to 4 mm. The corresponding energy density could reach 2.96 J/cm3 with a breakdown strength of 58 kV/mm for thickness of 1 mm.
authors: General Research Institute for Nonferrous Metals, Beijing 100088, China.
authors: Qingmeng
authors: Q
authors: Zhang
authors: Jun
authors: J
authors: Luo
authors: Qun
authors: Q
authors: Tang
authors: Dongfang
authors: D
authors: Han
authors: Yi
authors: Y
authors: Zhou
authors: Jun
authors: J
authors: Du
mesh_terms: D025802:Electric Capacitance; D004581:Electronics / Q000295:instrumentation*; D004735:Energy Transfer; D004867:Equipment Design; D019544:Equipment Failure Analysis; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000295:instrumentation*; D010316:Particle Size; D055672:Static Electricity