Colossal permittivity and high insulation resistivity in Dy- modified SrTiO3 lead-free ceramic materials with low dielectric loss

High performance colossal permittivity (CP) ceramic materials are indispensable for the development of electronic devices. In this work, excellent Sr1-xDyxTiO3 (0.000 <= x <= 0.018) ceramic samples were prepared through a traditional solid phase method. It can be found that the insulation resistivity of 4.7 x 10(7) Omega/cm(3) (DC 100V), the CP of 26712 and the low dielectric loss of 0.0065 (1 kHz) are obtained in x = 0.008 ceramic samples sintered in N-2. Based on the analysis of XRD, XPS and comparison of sintering in different atmospheres, the excellent dielectric property is mainly determined by defect dipoles associated with oxygen vacancy (eg.Ti'(Ti) - V-o(..) - Ti'(Ti)) These defect dipoles limit the long-range transition of electrons and result in electronic pinning effect. Additionally, it can be perceived that the insulation resistivity of 1.12 x 10(9) Omega/cm(3) (DC 100 V), the CP of 23134 and the low dielectric loss of 0.0098 (1 kHz) are achieved in x = 0.008 ceramic samples after reoxidation. According to the analysis of complex impedance spectroscopy, the improvement of the insulation resistivity of x = 0.008 ceramic samples is mainly attributed to the increase of the grain boundary resistance.