Ferromagnetic effect at smaller/larger grain size

[slayercantona]

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 $$\mu$$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.

 

[Gokul43201]

What do you know about the relationship between grain boundaries and ferromagnetic domain walls?

 

[slayercantona]

What do you know about the relationship between grain boundaries and ferromagnetic domain walls?

I don't know much more thing about them. But, I try to learn and solve their relationship. I read D6, 1/D, constant law some journals, but they don't give much more information. They are talked about just their size relationship, shortly. But, I wonder what is the reason of this changing?