کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7889047 | 1509796 | 2018 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Large temperature coefficient of resistance at near room temperature in Sr-doped La0.72Ca0.28MnO3:Ag0.2 polycrystalline composites
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
A series of La0.72Ca0.28âxSrxMnO3:Ag0.2 (x = 0.00, 0.01, 0.03, 0.05, 0.07, and 0.10) composites was prepared by sol-gel method using methanol as solvent. Sample composition was analyzed by X-Ray diffraction, which revealed that all samples are pseudo-perovskite. Grain size and morphology were characterized by scanning electron microscopy. The results showed that all samples are of high density and large grain size in the range of 50-100 µm. All samples exhibited sharp metal-insulator (M-I) transitions, along with a drastic transition from paramagnetism to ferromagnetism. With increased Sr doping, radius of A-site ion increased, both Curie temperature TC and M-I transition temperature shift to higher temperature increases, and transition width turns widener which makes a decreased temperature coefficient of resistance (TCR). Larger ionic radius of Sr2+, which resulted in enhancement of double exchange, enlarges Mn-O-Mn bond angle, hence improves electrical and magnetic properties. It was found that TCR could reach 24.3% Kâ1 by Ag addition at near room temperature, which makes this composite promising potential applications in infrared detection and night vision.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ceramics International - Volume 44, Issue 2, 1 February 2018, Pages 1778-1784
Journal: Ceramics International - Volume 44, Issue 2, 1 February 2018, Pages 1778-1784
نویسندگان
Yule Li, Qingming Chen, Zhiyu Li, Xiang Liu, Hui Zhang,