Study On Doping And Synthesis Of Nanosized Zirconia By Electrochemical Method

Based on the electrochemical properties of such metals as zirconium,aluminium and etc.. That is that metal element can not be obtained but its hydroxide or oxide can with electrochemical method. In this paper, ZrOCl2·8H2O as raw material, the nano-zirconia powders were synthesized with electrochemical method, and its formation mechanism was also explored. The phase of ZrO2 powders prepared with electrochemical method are cubic phase under 500℃, most cubic ZrO2 have transformed into monoclinic ZrO2 after calcined at 750℃for 2h, almost all of cubic ZrO2 have transformed into monoclinic ZrO2 after calcined at 1100℃for 2h.The volume change which along with phase transformation between monoclinic phase and tetragonal phase will cause instability of material properties, so its practical applications are often restricted. Tetragonal ZrO2 even cubic ZrO2 can exist stably at room temperature through doping small amount of rare earth metal oxides or alkaline earth metal oxides into matrix of zirconia, such as CaO, MgO, CeO2, etc.. In this paper, CaO, MgO, CeO2 and La2O3 were used as dopant and one or two of them was chose to dope ZrO2 powders, the effect of these four doping agents on the crystalline structure of ZrO2 was investigated.CaO, MgO and La2O3 were used as dopant and one of them was chosen to dope ZrO2 powders, the XRD patterns was used to investigated the effect of doping agents on the crystalline structure of ZrO2. CaO, MgO and La2O3 stabilized ZrO2 powders were prepared with electrochemical method, CaO, MgO and La2O3 can be fully dissolved into ZrO2 lattice and form substitution solid solution with ZrO2. CaO and La2O3 can restrain the phase transformation of ZrO2 powders from cubic phase to monoclinic phase under 1100℃. MgO stabilized ZrO2 powders can exist with cubic phase under 500℃.CaO, MgO, CeO2 and La2O3 were used as dopant and two of them were chosen to dope ZrO2 powders, the XRD patterns was used to investigated the effect of doping agents on the crystalline structure of ZrO2.CaO-MgO, CaO-La2O3, CeO2-La2O3 and MgO-CeO2 stabilized ZrO2 powders were prepared by electrochemical method. CeO2-La2O3 and MgO-CeO2 multi-doping can stabilize cubic ZrO2 powders under 750℃. CaO-MgO and CaO-La2O3 multi-doping can stabilize cubic ZrO2 powders under 1100℃.