کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1810624 1025566 2012 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Perturbed angular correlation study of 181Ta-doped PbTi1−xHfxO3 compounds
موضوعات مرتبط
مهندسی و علوم پایه فیزیک و نجوم فیزیک ماده چگال
پیش نمایش صفحه اول مقاله
Perturbed angular correlation study of 181Ta-doped PbTi1−xHfxO3 compounds
چکیده انگلیسی
In this work, the hyperfine quadrupole interaction at Ta-doped PbTi1−xHfxO3 polycrystalline samples is studied for the first time. Powders with x=0.25, 0.50 and 0.75 were prepared and characterized by X-ray diffraction analysis. Perturbed Angular Correlation (PAC) analyses were done as a function of temperature, using low concentration 181Ta nuclei as probes. In the ferroelectric and paraelectric phases of these compounds two sites were occupied by the probes. For each site the quadrupole frequency, asymmetry and relative distribution width parameters were obtained as a function of temperature above and below the Curie temperature (TC). One of these sites was assigned to the regular Ti-Hf site, while the other one was assigned to some kind of defect. The behavior of the hyperfine parameters as a function of temperature was analyzed in terms of a recent published phase diagram and the presence of disorder below and above TC. For the three compositions measured, the obtained hyperfine parameters present discontinuities which correspond to the ferroelectric-paraelectric phase transition. In both phases it was found broad frequency distributed interactions. The disorder in the electronic distribution would be responsible for the broad line width of the hyperfine interaction.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physica B: Condensed Matter - Volume 407, Issue 13, 1 July 2012, Pages 2610-2616
نویسندگان
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