کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10714004 | 1025564 | 2012 | 5 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
The quasi-magnetic-hysteresis behavior of polydisperse ferrofluids with small coupling constant
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موضوعات مرتبط
مهندسی و علوم پایه
فیزیک و نجوم
فیزیک ماده چگال
پیش نمایش صفحه اول مقاله

چکیده انگلیسی
The magnetization behaviors of ferrofluids based on γ-Fe2O3/Ni2O3 composite nanoparticles of size about 11 nm have been investigated. The dipole coupling constant λ of these particles is so small (0.43) that they cannot form aggregates through magnetic interaction alone. Experimental results have shown that for a polydisperse ferrofluid with a particle volume fraction of ÏV=2.4%, the magnetization curve exhibits quasi-magnetic-hysteresis behavior, i.e., the demagnetization curve lies above the magnetization curve in a high field. However, for a more dilute γ-Fe2O3/Ni2O3 ferrofluid with ÏV=0.94%, the magnetization curve does not show such behavior. According to the bidisperse model for polydisperse ferrofluids, these magnetization behaviors may be attributed to field-induced effects of self-assembled pre-existing chain-like aggregates. For such pre-existing chain-like aggregates, the orientation of the moments inside the particles is not co-linear, so that during the magnetization and demagnetization processes, their apparent magnetizations at the high-field limit are different. As a consequence, the magnetization curve of the ferrofluid with ÏV=2.4% displays quasi-magnetic-hysteresis.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physica B: Condensed Matter - Volume 407, Issue 24, 15 December 2012, Pages 4638-4642
Journal: Physica B: Condensed Matter - Volume 407, Issue 24, 15 December 2012, Pages 4638-4642
نویسندگان
Jian Li, Yueqiang Lin, Xiaodong Liu, Lihua Lin, Qingmei Zhang, Jun Fu, Longlong Chen, Decai Li,