期刊
JAPANESE JOURNAL OF APPLIED PHYSICS
卷 48, 期 12, 页码 -出版社
JAPAN SOC APPLIED PHYSICS
DOI: 10.1143/JJAP.48.127002
关键词
-
资金
- Japan Society for the Promotion of Science
The nonlinear Brownian rotational relaxation of magnetic fluids for the case of large excitation field was studied in relation to its biomedical applications. The Fokker-Planck equation, which describes the nonlinear behavior of magnetic fluids, was solved by numerical simulation when a large step or a sinusoidal field was applied. Deviations from the Debye theory were quantitatively clarified. First, it was shown that the response time of the magnetic fluids became shorter than the Brownian relaxation time for a larger excitation field, which can be expressed in terms of the field-dependent Brownian relaxation time. Next, the amplitude of the ac susceptibility became lower for larger excitation fields, and the frequency characteristic of the ac susceptibility moved to a higher frequency compared with that predicted by the Debye theory. Finally, higher harmonics occurred with increasing excitation fields. Approximate equations, that describe such nonlinear behaviors reasonably well, were also obtained. These equations are expected to be useful for developing biosensors based on Brownian relaxation. (C) 2009 The Japan Society of Applied Physics
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据