Phase Stability and Preparation of Lead Perovskite Dielectrics

We studied the phase stability of Pb(AxBy)03 compositions containing a combination of pentavalent cation and divalent or trivalent cations. It was found that Co(2+) and Fe(3+), in combination with Nb or Ta, favor the formation of perovskite structure. With other divalent or trivalent cations, pyrochlore may form as a competing or dominant phase. We investigated the use of precursors to prepare Pb(Ni1/3Nb2/3)03, Pb(Mg1/3Nb2/3) 03-Pb(Zn1/3Nb2/3)03 solid solutions and we prepared single phase perovskites with 7-10 times higher dielectric constants than those by conventional powder mixture process.