کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1803389 | 1024616 | 2006 | 4 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Magnetic resonances spectroscopy of nanosize particles La0.7Sr0.3MnO3
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
فیزیک و نجوم
فیزیک ماده چگال
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Using a co-precipitation method, perovskite-type manganese oxide La0.7Sr0.3MnO3 nanoparticles (NPs) with particle size 12Â nm were prepared. Detailed studies of both 55Mn nuclear magnetic resonance and superparamagnetic resonance spectrum, completed by magnetic measurements, have been performed to obtain microscopic information on the local magnetic structure of the NP. Our results on nuclear dynamics provide direct evidence of formation of a magnetically dead layer, of the thickness â2Â nm, at the particle surface. Temperature dependences of the magnetic resonance spectra have been measured to obtain information about complex magnetic properties of La0.7Sr0.3MnO3 fine-particle ensembles. In particular, electron paramagnetic resonance spectrum at 300Â K shows a relatively narrow sharp line, but as the temperature decreases to 5Â K, the apparent resonance field decreases and the line width considerably increases. The low-temperature blocking of the NPs magnetic moments has been clearly observed in the electron paramagnetic resonances. The blocking temperature depends on the measuring frequency and for the ensemble of 12Â nm NPs at 9.244Â GHz has been evaluated as 110Â K.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Magnetism and Magnetic Materials - Volume 300, Issue 1, May 2006, Pages e122-e125
Journal: Journal of Magnetism and Magnetic Materials - Volume 300, Issue 1, May 2006, Pages e122-e125
نویسندگان
Vladimir Krivoruchko, Tat'yana Konstantinova, Anton Mazur, Andrey Prokhorov, Victor Varyukhin,