کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1808337 | 1525155 | 2016 | 7 صفحه PDF | دانلود رایگان |
A series of La doped lead titanate samples, with composition Pb1−xLaxTi1−x/4O3 (PLTx), where x=0.00; 0.02; 0.04; 0.06; 0.07; 0.08; 0.10; 0.12; 0.14; 0.16; 0.18; 0.21 and 0.22 was prepared using the sol–gel process.Addition of La gives rise to the two well-known phenomena: diffuseness and relaxation around the ferro-to-paraelectric transition; the two parameters related to these phenomena, and which give a satisfactory interpretation of them, have been estimated using the Uchino's quadratic law. This diffuse phase transition (DPT) has been investigated with the help of the Landau–Devonshire cluster theory and the model of Cheng et al., to show that polar regions may be generated around the DPT and far from the temperature, Tm, of the maximum of the dielectric permittivity, which have as a direct consequence a non vanishing polarization even if T>Tm.
Journal: Physica B: Condensed Matter - Volume 494, 1 August 2016, Pages 26–32