The effect of chromium addition on the structure and electrical properties of CaCu3Ti4O12 is studied.Compositions based on the formula CaCu3Ti4-xCrxO12-σ(x = 0, 0.025, 0.050 and 0.075 mol%) are prepared by solid-stat...The effect of chromium addition on the structure and electrical properties of CaCu3Ti4O12 is studied.Compositions based on the formula CaCu3Ti4-xCrxO12-σ(x = 0, 0.025, 0.050 and 0.075 mol%) are prepared by solid-state reaction. Pellets sintered at 1070℃ for 12 h are characterised by X-ray diffraction, scanning electron microscopy/energy dispersive spectroscopy and impedance spectroscopy. Current densityelectric field, dielectric loss and permittivity measurements are also carried out. Rietveld refinement showed the substitution of Cr(Ⅲ) on the Ti(Ⅳ) site, with the maximum substitution for x = 0.025 mol%.The generation of electrical defects in the grain boundary region by chromium doping is responsible for increasing the electric breakdown field strength and nonlinearity coefficient at room temperature from 1723 V/cm and 5.29 for x = 0 mol% to 3431 V/cm and 8.16 for x = 0.025 mol%. This composition shows the greatest improvement in ceramic varistor parameters.展开更多
基金the Complexo de Laboratórios Multiusuários(C-Labmu/UEPG)and CAPES,CNPq,Fundacao Araucária,Ministerio de Economía y Competitividad(project MAT2016-80410-P)and to“Universitat Jaume I”-project No.UJIB-2016-38 for financial support.
文摘The effect of chromium addition on the structure and electrical properties of CaCu3Ti4O12 is studied.Compositions based on the formula CaCu3Ti4-xCrxO12-σ(x = 0, 0.025, 0.050 and 0.075 mol%) are prepared by solid-state reaction. Pellets sintered at 1070℃ for 12 h are characterised by X-ray diffraction, scanning electron microscopy/energy dispersive spectroscopy and impedance spectroscopy. Current densityelectric field, dielectric loss and permittivity measurements are also carried out. Rietveld refinement showed the substitution of Cr(Ⅲ) on the Ti(Ⅳ) site, with the maximum substitution for x = 0.025 mol%.The generation of electrical defects in the grain boundary region by chromium doping is responsible for increasing the electric breakdown field strength and nonlinearity coefficient at room temperature from 1723 V/cm and 5.29 for x = 0 mol% to 3431 V/cm and 8.16 for x = 0.025 mol%. This composition shows the greatest improvement in ceramic varistor parameters.
