کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8003138 | 1516316 | 2013 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Influence of Li and La content on phase structures and electrical properties of K0.5Na0.5NbO3 lead-free piezoelectric ceramics
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
فلزات و آلیاژها
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Lead-free piezoceramics (K0.5Na0.5)1â2xLixLaxNbO3 (where x = 0.050, 0.055, 0.060, and 0.065) have been fabricated by a conventional sintering technique. The effect of Li and La doping on the phase structure and electrical properties of (K0.5Na0.5)1â2xLixLaxNbO3 ceramics was investigated. X-ray diffraction analysis showed that the ceramics possess a perovskite structure with orthorhombic symmetry. A small amount of second phase (K6Li4Nb10O30, â¼3%) was present in KNLLN ceramics. Ferroelectric-paraelectric phase transition temperature decreases with increase in doping content. La-doping in the ceramics displayed a relative lower loss tangent (tan δ) from room temperature up to 350 °C. Detailed studies of dielectric and electrical properties indicate that the Curie temperature shifted to lower temperature with the increase in Li and La doping. Moreover, the dielectric maxima dropped down rapidly and the dielectric peaks became extremely broad. The weak dielectric properties for the samples of x = 0.065 can be ascribed to the formation of pseudo-cubic structures at high level of Li and La substitution. The AC conductivity increases with increase in temperature showing a negative temperature coefficient of resistance (NTCR) behavior. The low value of activation energy obtained for the ceramic samples could be attributed to the influence of electronic contribution to the conductivity.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Alloys and Compounds - Volume 577, 15 November 2013, Pages 575-580
Journal: Journal of Alloys and Compounds - Volume 577, 15 November 2013, Pages 575-580
نویسندگان
Radheshyam Rai, Rashmi Rani, Seema Sharma, Andrei L. Kholkin,