Effect of preparative parameters on the formation of perovskite pmn ceramic

Relative permittivity measurements performed on the perovskite lead magnesium niobate (PMN) ceramic synthesized by the conventional (M-I) and Swartz's (M-II) methods in the light of preparative parameters like calcination and sintering conditions along with the addition of excess PbO and MgO are reported. The results suggest that the relative permittivity exhibits a maximum for the specimen having uniform distribution of fine pyrochlore (PMNC) grains of size <0.6 microns in the matrix of PMN. In addition to this, it is also found that the method M-II is superior to M-I. The formation of PMN is found to be critical to the excess PbO and MgO in case of M-I and M-II respectively.

Keywords:

• synthesis
• perovskites
• pyrochlores
• microstructure
• dielectric properties