By applying inverse titration chemical co-precipitation to obtain NiFe_2O_4, MgFe_2O_4, CdFe_2O_4 and Zn_0.5Ni_0.5Fe_2O_4 nano-powders, the best techniques of above materials were acquired.

• 采用反滴定化学共沉淀法制备出了NiFe_2O_4、MgFe_2O_4、CdFe_2O_4和Zn_(0.；5)Ni_(0