Method to Identify the Material of a Single Grain Based on Its Magnetization and Anisotropy Measured in a Chamber Type μG Drop Shaft
Free translation caused by attractive field-gradient force was observed for Ni and ferrite(CuFe2O4)grains that were released in a diffuse area.In order to exclude the effect of terrestrial gravity,translation was observed in micro-gravity(μG)condition produced by a compact drop-shaft installed in a ordinary laboratory room.Magnetization Ms per unit mass of the grain is obtained by analyzing the above-mentioned translations in terms of a energy conservation rule; here conservation of the sum of field-induced potential mMsH and kinetic energy 1/2mv2 is considered for a particle with mass m.The present method of obtaining Ms is free of measuring the mass of sample; this is because the field-gradient force is a volume force that is proportional to m.The method is also free of an interfering signal emitted from the sample holder.Accordingly,Ms is detectable irrespective of sample size,provided that the field-induced translation is observable.The above-mentioned procedure to estimate Ms from filed-induced translation is a step to obtain a reliable magnetic data from a single nano-sized grain.The efficiency of material identification was recently confirmed on various solid grains,which was based on diamagnetic magnetization data obtained from its translations caused by field-gradient repulsive force.A diamagnetic material generally possesses an intrinsic value of magnetic susceptibility and its anisotropy.The present results on nickel grains indicate that the principle of material identification based on its magnetization data is applicable for the three major category of magnetic materials,namely ferro-(or ferri-)magnetic,paramagnetic and diamagnetic material..
chamber type μG drop-shaft saturated magnetization field-gradient force magnetic ejection diamagnetic anisotropy magnetic orientation magnetic alignment
UYEDA Chiaki HISAYOSHI Keiji MAMIYA Mikio NAGAI Yasuo
Graduate School of Science.Osaka University,Toyonaka 560-0043,Osaka,Japan AIST Tsukuba,Ibaragi,Japan
国际会议
The 7th International Conference on Electromagnetic Processing of Materials(第七届冶金与材料电磁过程国际大会)
北京
英文
1-4
2012-10-22（万方平台首次上网日期，不代表论文的发表时间）