On the other hand, the size-dependent magnetic properties of metallic NPs have also attracted great interest from physicists. For example, it had been reported that atomic magnetic moment could be enhanced in ferromagnetic NPs , or even be induced in sub-nano clusters of non-FM metals such as Rh and thiolcapped Au . Moreover, the critical point (typically Curie temperature 𝑇 ! and Neel temperature 𝑇 " ) of nano-scale magnets also presents a notable finite size effect in experiments and theories . As for FM materials, 𝑇 ! is generally expected to be reduced with the decreasing grain size of the NP as a finite-size scaling relationship :