A new method for the preparation of compositionally homogeneous and pyrochlore-free solid solution of Pb(Mg1/3Ta2/3)O3–Pb(Yb1/2Ta1/2)O3 system

A new method was developed for the synthesis of solid solution of Pb(Mg1/3Ta2/3)O3–Pb(Yb1/2Ta1/2)O3 (PMYT) system having no compositional fluctuation. This method is a combination of wet and dry processes. At the first stage, the homogeneous mixture of MgO and Yb2O3 (MY-powder) was prepared through a wet process. Then the dry process was performed in a solid-state reaction among the MY-powder, PbO, and Ta2O5 to obtain PMYT. The powder X-ray diffraction analysis revealed that PMYT prepared by this wet–dry combination method had practically no compositional fluctuation; it was difficult to eliminate the compositional fluctuation through the conventional dry method. Another advantage of the wet–dry combination method is that pyrochlore-free PMYT can be obtained. This is due to the high reactivity of the MY-powder. In the combination method, the wet process has to be applied to only two species of the B-site cations. Thus, it can be used for the preparation of many Aa+(BIb+xBIIc+1−x)f(x)BIIId+1−f(x)O32− (f(x) = (6 − a − d)/{bx + c(1 − x) − d}, and b < c < 6 − a < d, or b > c > 6 − a > d)-type solid solutions effectively.