کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10624958 989613 2014 19 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Synthesis of negative thermal expansion HfW2O8 thin film using pulsed laser deposition
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Synthesis of negative thermal expansion HfW2O8 thin film using pulsed laser deposition
چکیده انگلیسی
HfW2O8 thin films were grown on quartz substrates using a pulsed-laser deposition method at various temperatures from room temperature to 500 °C and different oxygen pressures from 5 Pa to 20 Pa. The effects of substrate temperatures, oxygen pressures and post-annealing on the phase compositions and morphologies of the obtained HfW2O8 thin films were systematically investigated using X-ray diffraction (XRD) and a field emission scanning electron microscope (FESEM). The thermal expansion properties of the cubic HfW2O8 thin films were characterized using high temperature X-ray diffraction (HTXRD). Results indicate that the as-deposited HfW2O8 thin films show amorphous phases. Crystallized cubic HfW2O8 thin films can be prepared by heating at 1200 °C for 7 min. HfW2O8 thin film grown at 500 °C with an oxygen pressure of 5 Pa displayed the smoothest and uniform surface morphologies. The high temperature X-ray diffraction analyses demonstrate that the cubic HfW2O8 thin film exhibits strong negative thermal expansion and an α to β structure phase transition occurred between 100 °C and 150 °C. Its average linear thermal expansion coefficient was calculated to be −9.33×10−6 K−1 from 25 °C to 600 °C.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ceramics International - Volume 40, Issue 9, Part A, November 2014, Pages 13855-13859
نویسندگان
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