کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1801561 | 1024572 | 2008 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
The effect of annealing process on the physical properties of La1âxNaxMnOy
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
فیزیک و نجوم
فیزیک ماده چگال
پیش نمایش صفحه اول مقاله

چکیده انگلیسی
The effect of Na doping and annealing time on the structure, electrical properties, magnetoresistance and thermopower properties has been investigated in perovskite La1âxNaxMnOy (x=0.025, 0.075 and 0.1) systems. La1âxNaxMnOy crystallizes in a single-phase rhombohedral structure. It is observed a simultaneous occurrence of the ferromagnetic to paramagnetic state and metallic to insulating state. In the meanwhile, a large negative magnetoresistance with low applied magnetic field is observed. In addition, Ï(T) curves for Na-doped samples exhibit another broad transition Tms2 below Tms. Such double peak behavior in the Ï(T) curve interpreted by the electronic inhomogeneity in the samples. The sign of S changes from positive to negative depending on composition. The values of Seebeck coefficient are small (in the microvolt range).
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Magnetism and Magnetic Materials - Volume 320, Issue 6, March 2008, Pages L43-L49
Journal: Journal of Magnetism and Magnetic Materials - Volume 320, Issue 6, March 2008, Pages L43-L49
نویسندگان
A.M. Ahmed, S.A. Saleh, E.M.M. Ibrahim, E. Bontempi, H.F. Mohamed,