کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5437952 | 1398179 | 2017 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Phase structural transition and microwave dielectric properties in isovalently substituted La1âxLnxTiNbO6 (Ln=Ce, Sm) ceramics
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
سرامیک و کامپوزیت
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چکیده انگلیسی
Aeschynite-type La1âxLnxTiNbO6 (Ln=Ce, Sm, x=0-1) ceramics were prepared via a conventional solid state method. Analysis of X-ray diffraction, Raman, infrared reflectivity spectra and the microstructures revealed a series of composition-induced phase evolution in sequence: monoclinicâcoexistence of monoclinic and orthorhombicâorthorhombic structure, i.e. MâM+OâO. The critical compositions of distinguishing the dominant M or O phase were x=0.15 in La1âxCexTiNbO6 and x=0.10 in La1âxSmxTiNbO6 ceramics, exactly corresponding to the average ionic radius of rare earth ions (IR) ~1.027Â Ã
. The crystal structure and microwave dielectric properties of RETiNbO6 (RE=rare earth) ceramics strongly depended on IR. Near-zero Ïf was achieved in the Ce-sample with x=0.153 (εr=28.9, QÃf=17,275 GHz@6.54 GHz) as well as in the Sm-sample with x=0.098 (εr=28.2, QÃf=19,186 GHz@6.78 GHz). Eventually, RETiNbO6 would form O euxenite (-Ïf), O aeschynite (+Ïf), and M aeschynite (-Ïf), as IR<0.945 Ã
, 0.945Â Ã
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ceramics International - Volume 43, Issue 9, 15 June 2017, Pages 7065-7072
Journal: Ceramics International - Volume 43, Issue 9, 15 June 2017, Pages 7065-7072
نویسندگان
Jian Zhang, Ruzhong Zuo,