کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8157971 1524874 2013 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Physical properties of antiferromagnetic Mn doped ZnO samples: Role of impurity phase
موضوعات مرتبط
مهندسی و علوم پایه فیزیک و نجوم فیزیک ماده چگال
پیش نمایش صفحه اول مقاله
Physical properties of antiferromagnetic Mn doped ZnO samples: Role of impurity phase
چکیده انگلیسی
Structural, morphological, optical, and magnetic properties of nanocrystalline Zn1−xMnxO samples (x=0.01, 0.02, 0.04, 0.06, 0.08 and 0.10) prepared by the sol-gel route are studied by X-ray diffraction (XRD), Scanning electron microscopy (SEM), UV-visible absorption spectroscopy, Superconducting quantum interference device (SQUID) magnetometry and positron annihilation lifetime spectroscopy (PALS). XRD confirms formation of wurzite structure in all the Mn-substituted samples. A systematic increase in lattice constants and decrease in grain size have been observed with increase in manganese doping concentration up to 6 at% in the ZnO structure. An impurity phase (ZnMnO3) has been detected when percentage of Mn concentration is 6 at% or higher. The optical band gap of the Mn-substituted ZnO samples decrease with increase in doping concentration of manganese whereas the width of the localized states increases. The antiferromagnetic exchange interaction is strong in the samples for 2 and 4 at% of Mn doping but it reduces when the doping level increases from 6 at% and further. Positron life time components τ1 and τ2 are found to decrease when concentration of the dopant exceeds 6 at%. The changes in magnetic properties as well as positron annihilation parameters at higher manganese concentration have been assigned as due to the formation of impurity phase.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Magnetism and Magnetic Materials - Volume 346, November 2013, Pages 130-137
نویسندگان
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