Synthesis of a solid solution of PbTiO3-PbZrO3-Pb (Mg1/3Nb2/3)O3 system through use of 8-quinolinol and its properties

A new method for the synthesis of a solid solution of PbTiO₃-PbZrO₃-Pb (Mg_1/3Nb_2/3)O₃ system (PZTMN) has been developed. An aqueous solution of Ti⁴⁺, Zr⁴⁺, Mg²⁺ and Nb⁵⁺ was dropped into a solution of 8-quinolinol in aqueous ammonia. The precipitate formed was washed, dried and fired, then an oxide (ZTMN) was obtained. The best firing temperature for the precipitate was 700 °C. The ZTMN powder was then mixed with PbO powder: when this mixture was fired, PZTMN was formed directly. By a conventional solid-state reaction among PbO, ZrO₂, TiO₂, MgO and Nb₂O₅ (P + Z + T + M + N] method), PbTiO₃ and Pb(Mg_1/3Nb_2/3)O₃ were formed as intermediate products during the reaction. The single phase of PZTMN was obtained at 1200 °C for the P + Z + T + M + N] method and at 800 °C for the new P + ZTMN] method. The compositional fluctuation of PZTMN prepared by the P + ZTMN] method was very small, and its dielectric constant was much higher than that of PZTMN prepared by the P + Z + T + M + N] method. The density of PZTMN prepared by the P + ZTMN] method practically attained the theoretical density under conditions of calcining at 800 °C and sintering at 1100 °C for 1 h.