Authors: Shujie Duan Qiwu Shi Wanxia Huang Yaxin Zhang Shen Qiao Yang Xiao
Publish Date: 2016/02/27
Volume: 27, Issue: 6, Pages: 6318-6324
Abstract
Strontium Calcium titanate SCT Sr1−xCaxTiO3 nanopowders have been successfully synthesized by sol–gel method The effect of Ca2+ ion content from 0 to 1 on their crystal structure microstructure transmission and dielectric properties in terahertz range was systematically investigated The results revealed that single SCT phases with well crystallinity were formed at 900 °C for 2 h The grain size of the SCT powders was decreased by increasing the Ca2+ ion molar ratios Xray diffraction XRD and Raman spectra measurement results demonstrated that obvious reduction of symmetry and Raman modes related to structural information varied with the Ca2+ ion composition x The sequence of SCT phase transitions with increasing Ca content is from cubic through tetragonal I4/mcm to orthorhombic Pbnm The THz transmission of SCT revealed by terahertz timedomain spectroscopy was changed by varying the Ca2+ ion composition Meanwhile the time lag between reference and the SCT could be adjusted between around 20 ps and 30 ps which increased with increased Ca content The permittivity of stressed Sr1−xCaxTiO3 powders was obtained by terahertz timedomain spectroscopy These results revealed that the Ca2+ ion in SCT led to tuning of dielectric response in terahertz range Sr09Ca01TiO3 exhibited a smearedout maximum for x ≥ 03 the real and imaginary components of dielectric permittivity ε′ and ε″ decreased with increasing x These results may offer considerable insights into the application of Sr1−xCaxTiO3 in smart THz deviceThis work was financially supported by the National Natural Science Foundation of China Grants 61271075 11404226 and the Postdoctoral Science Foundation of China Grants 2014M550468 We thank the Analytical and Testing Center of Sichuan University for the XRD analysis
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