کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1802424 | 1024597 | 2007 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Magnetic and magnetoresistivity properties of nanocrystalline Nd0.7Sr0.3MnO3
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
فیزیک و نجوم
فیزیک ماده چگال
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Magnetic and magnetoresistivity properties of nanocrystalline Nd0.7Sr0.3MnO3 Magnetic and magnetoresistivity properties of nanocrystalline Nd0.7Sr0.3MnO3](/preview/png/1802424.png)
چکیده انگلیسی
Nanocrystalline Nd0.7Sr0.3MnO3 sample with an average particle size of 40Â nm has been synthesized by citrate-complex method. The temperature-dependent magnetization shows the absence of long-range ferromagnetic (FM) order. The electron magnetic resonance study indicates the presence of magnetic inhomogeneity below 290Â K. Electrical conductivity follows variable range hopping mechanism in paramagnetic (PM) regime. The low-temperature insulator-like resistivity seems to obey non-tunneling conductivity mechanism. The magnetoresistivity (MR) increases with decreasing temperature down to magnetic transition temperature (TC) and saturates below TC. The MR does not follow spin polarized tunneling mechanism in FM regime. The above results could be best described by spin-dependent hopping between the localized spin clusters together with the phase separation phenomenon. It is assumed that the clusters form due to the distribution of canted spins all over the volume of the nanoparticles and these canted spins prompt the itinerant electrons to localize. The analysis of the MR reveals that FM phase contributes to the total MR at low applied magnetic fields, whereas the PM phase contributes at relatively high fields. The above model quantitatively explains the observed MR.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Magnetism and Magnetic Materials - Volume 308, Issue 1, January 2007, Pages 28-34
Journal: Journal of Magnetism and Magnetic Materials - Volume 308, Issue 1, January 2007, Pages 28-34
نویسندگان
C. Krishnamoorthy, K. Sethupathi, V. Sankaranarayanan, R. Nirmala, S.K. Malik,