title: Doped nanocrystalline ZnO powders for non-linear resistor applications by spray pyrolysis method.
abstract: Homogeneous and doped nanocrystalline ZnO powders (30-200 nm) were synthesized by spray pyrolysis technique. The spray pyrolysed powders were calcined in the temperature range of 500-750 degrees C. Formation of insulating pyrochlore phase started from 700 degrees C during the calcination itself. The calcined powders were compacted and sintered at different temperatures ranging from 900-1200 degrees C for 0.5-4 h. The densification behavior was found to be dependent on calcination temperature of the nanopowder. The resulting discs were found to have density (5.34-5.62 g/cc) in the range of 96-99% of theoretical density. The breakdown voltage value obtained for the nanopowder based non-linear resistor is 10.3 kV/cm with low leakage current density of 0.7 microA/cm2 and coefficient of nonlinearity as high as 193. The activation energy for grain growth of the doped ZnO nanopowder powders is 449.4 +/- 15 kJ/mol.
authors.affiliation: International Advanced Research Center for Powder Metallurgy and New Materials (ARCI), Balapur PO, Hyderabad 500005, India.
authors.forename: Kaliyan
authors.initials: K
authors.lastname: Hembram
authors.forename: R
authors.initials: R
authors.lastname: Vijay
authors.forename: Y S
authors.initials: YS
authors.lastname: Rao
authors.forename: T N
authors.initials: TN
authors.lastname: Rao