Hi everybody, I have faced with a problem in my report. The question said that "How can ferromagnetic effect change to depend on particle/grain size(at nm (10, 50, 100, 1000...) and at [tex]\mu[/tex]m (0.5, 1, 2...)?" (In shortly, what can we observe at feromagnetic effect if we increase and decrease of particle/grain size?). In my opinion, if I have so small particle, I can not observe any ferromagnetic effect or have medium size we can observe, but it will be larger than old, I cannot observe ferromagnetic effect again. But, I cannot explain the reason of these results. (Maybe my answers can be wrong). Has anybody know the answers of my questions? I look forward to your answers. Thanks for everything.