Novel Raman spectroscopy of a strong high-k diffuse phase transition (Ba<sub>1∿span style='font-style: italic'>xsub>Sm<sub>xsub>)(Ti<sub>0.95∿span style='font-style: italic'>x/4sub>Ce<sub>0.05sub>)O<sub>3sub> ceramics

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• 作者：Dan-Dan Han ; Qiao-li Liu ; Yan-Dong Wang ; Chang-Hao Wang ; Da-Yong Lu<sup> ; sup><sup>cninjp11232000@yahoo.com" class="auth_mail" title="E-mail the corresponding authorsup><sup> ; sup><sup>dylu@jlict.edu.cn" class="auth_mail" title="E-mail the corresponding authorsup>
• 关键词：B. Defects ; C. Dielectric properties ; D. BaTiO3 and titanates ; Powders ; solid state reaction and sintering
• 刊名：Ceramics International
• 出版年：2016
• 出版时间：15 May 2016
• 年：2016
• 卷：42
• 期：7
• 页码：8815-8821
• 全文大小：3631 K

文摘

Novel Raman spectra were discovered in (Ba<sub>1&minus;m>xm>sub>Sm<sub>m>xm>sub>)(Ti<sub>0.95&minus;m>xm>/4sub>Ce<sub>0.05sub>)O<sub>3sub> (0.03≤m>xm>≤0.10) ceramics and investigated in relation to the fluorescent effect of Sm<sup>3+sup> ions. Special interest was paid to analyze the dielectric response and defect chemistry associated with the structural evolution by X-ray diffraction (XRD), scanning electron microscopy (SEM), electron paramagnetic resonance (EPR), Raman spectroscopy (RS), and dielectric measurements. Complete solid solutions, known as BS5TC5 and BS6TC5 for (Ba<sub>1&minus;m>xm>sub>Sm<sub>m>xm>sub>)(Ti<sub>0.95&minus;m>xm>/4sub>Ce<sub>0.05sub>)O<sub>3sub> ceramics were found to form at m>xm>=0.05 and 0.06 (approximately) and exhibit a cubic structure and a non-uniform microstructure. BS6TC5 exhibited a strong high-m>k  m> diffuse phase transition (DPT) behavior (mmlsi0003" class="mathmlsrc">mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0272884216300645&_mathId=si0003.gif&_user=111111111&_pii=S0272884216300645&_rdoc=1&_issn=02728842&md5=74582dabb24de1d7399948fbb490bc34">mg class="imgLazyJSB inlineImage" height="11" width="11" alt="View the MathML source" style="margin-top: -5px; vertical-align: middle" title="View the MathML source" src="/sd/grey_pxl.gif" data-inlimgeid="1-s2.0-S0272884216300645-si0003.gif">mathContainer hidden">mathCode"><math altimg="si0003.gif" overflow="scroll"><mrow><msubsup subscriptshift="90%" superscriptshift="100%"><mrow><mi>ϵmi>mrow><mrow><mi mathvariant="normal">mmi>mrow><mrow><mo accent="true" form="prefix">&prime;mo>mrow>msubsup>mrow>math>=9300, m>Tm><sub>Csub>=78 °C), a lower dielectric loss (tan m>δm><0.05), and a feature of mixed valence at Ba sites (Sm<sup>3+sup>, Ce<sup>3+sup>) and Ti sites (Sm<sup>3+sup>, Ce<sup>4+sup>). The BSTC ceramics with m>xm>=0.09 met the Y5V specification. A weak m>gm>=2.004 EPR signal associated with ionized Ti-vacancy defects appeared in single-phase ceramics.