کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
80982 49412 2007 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
On the room-temperature ferromagnetism of Zn1−xCrxO thin films deposited by reactive co-sputtering
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
پیش نمایش صفحه اول مقاله
On the room-temperature ferromagnetism of Zn1−xCrxO thin films deposited by reactive co-sputtering
چکیده انگلیسی

We report on the preparation and detailed characterization of ferromagnetic (FM) Zn1−xCrxO thin films deposited on Si substrates using reactive co-sputtering of Cr and Zn in controlled oxygen atmosphere. X-ray diffraction (XRD) data showed wurtzite ZnO peaks in the FM films prepared with lower Cr sputter powers, whose position and intensities are influenced by Cr doping. However, samples prepared with higher Cr powers did not show ferromagnetism but displayed evidence of Cr2O3 and ZnCr2O4 phases with no zinc oxide (ZnO) phase. The magnetization is higher (saturation magnetization Ms=18 emu/cm3) for lower Cr concentrations and decreases for higher Cr doping. The samples were investigated extensively to understand the film composition, dopant distribution, homogeneity and potential origin of the observed ferromagnetism. Particle-induced X-ray emission (PIXE) studies were employed to determine the chemical composition as well as the Cr/Zn ratio in the films. Film uniformity and homogeneity, investigated using Rutherford backscattering spectrometry, showed a relatively uniform ZnO layer in the as-prepared samples but, in a sample annealed at 800 °C, showed some diffusion of Si from the substrate. X-ray photoelectron spectroscopy (XPS) studies indicated that Cr ions are in the oxidized state, but showed changes in the binding energy and Cr concentration when measured after removing 10 nm from the surface using Ar ion sputtering. Possible origins of the observed FM behavior are discussed based on the comprehensive characterization results.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Solar Energy Materials and Solar Cells - Volume 91, Issues 15–16, 22 September 2007, Pages 1496–1502
نویسندگان
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