Structural characterizations, dielectric properties and impedance spectroscopy analysis of NdxSr1-1.5xTiO3 ceramics

• Published in: Journal of electroceramics 2013, Vol.31 (1-2), p.117-123
• Main Authors: Luo, Wen-Qin, Shen, Zong-Yang, Li, Yue-Ming, Wang, Zhu-Mei, Liao, Run-Hua, Gu, Xing-Yong
• Format: Article
• Language: English
• Subjects: Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Composites; Crystallography and Scattering Methods; Electrochemistry; Glass; Materials Science; Natural Materials; Optical and Electronic Materials
• ISSN: 1385-3449; 1573-8663
• DOI: 10.1007/s10832-013-9805-0

The Nd x Sr 1–1.5 x TiO 3 ceramics ( x  = 0, 0.008, 0.024, 0.056, 0.104, 0.152 and 0.200) were prepared by solid state reaction method. X-ray diffraction (XRD) results indicated pure perovskite phase for all ceramics and the structure changed from cubic to tetragonal by increasing x value. Scanning electron microscopy (SEM) images showed high dense microstructure for all ceramics, and the grain size was strongly suppressed to ~1 μm for Nd x Sr 1–1.5 x TiO 3 ceramics with x  = 0.008, then gradually increased by further increasing x value and reached ~10 μm when x  = 0.200. The relative dielectric constant ε r was strongly enhanced to 5,060 for the sample with x  = 0.024, while its dielectric loss tan δ was still lower than 0.03. Together with its relatively high breakdown strength E b  > 10 kV/mm, this ceramic should be a good candidate for high-voltage capacitor applications with enhanced energy storage densities. Impedance spectroscopy analysis revealed that the Nd x Sr 1–1.5 x TiO 3 ceramics showed electrically heterogeneous, and the space charge polarization at interfaces should contribute to the observed high dielectric constant ε r .