کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7990500 | 1516129 | 2018 | 30 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
(Pb1-xBix)(Ti1-xMnx)O3: Competing mechanism of tetragonal-cubic phase on A/B site modifications
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
فلزات و آلیاژها
پیش نمایش صفحه اول مقاله

چکیده انگلیسی
Structural, vibrational and dielectric properties of (Pb1-xBix)(Ti1-xMnx)O3 (PBTM) (0â¯â¤â¯xâ¯â¤â¯0.50) polycrystalline ceramics have been examined as a function of temperature. Synchrotron-based powder x-ray diffraction was employed to confirm phase purity and crystal structures of the samples. Tetragonality (c/a ratio) of the PBTM system increased to 1.066 from 1.064 for the compositions xâ¯=â¯0.12 for pure PbTiO3 sample and decreased with further increase in x (â¥0.18). The temperature of phase transition increased to a maximum of 773â¯K for the sample xâ¯=â¯0.09. The peak corresponding to the ferroelectric-paraelectric phase transition for xâ¯=â¯0.09 sample was accompanied by a change in crystal structure from tetragonal to cubic at â¼773â¯K, as confirmed by the temperature dependent XRD data. Unit cell volume was found to decrease with increase in temperature, indicating the existence of a negative coefficient of thermal expansion in all samples up to the temperature of phase transitions. The thermal coefficients were found to be â1.571â¯Ãâ¯10â5/K, â2.44â¯Ãâ¯10â5/K, and â0.50â¯Ãâ¯10â5/K for xâ¯=â¯0, 0.06, and 0.09 samples, respectively. Raman spectra showed softening of the transverse optical phonon modes and their full width at half maxima (FWHM) increased with the increase in composition. Field-emission scanning electron microscope equipped with energy dispersive x-ray spectrometer (EDS) confirmed compositional homogeneity and dense-type microstructure.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Alloys and Compounds - Volume 765, 15 October 2018, Pages 278-286
Journal: Journal of Alloys and Compounds - Volume 765, 15 October 2018, Pages 278-286
نویسندگان
Arun Kumar Yadav, Anita Verma, Birender Singh, Deepu Kumar, Sunil Kumar, Velaga Srihari, Himanshu K. Poshwal, Pradeep Kumar, Shun-Wei Liu, Sajal Biring, Somaditya Sen,