Effect of lithium carbonate on the ferroelectric properties of lead ferroniobate ceramics

We have studied the grain and crystal structures and the dielectric (300–700 K) and piezoelectric characteristics of ceramic samples of unmodified multiferroic lead ferroniobate and materials modified with lithium carbonate above stoichiometry during synthesis. The addition of the modifier has been shown to improve the microstructure of the samples, increase their resistivity, improve their dielectric controllability, and raise their piezoelectric activity. The observed effects have been tentatively attributed to the formation of Li-containing liquid phases during synthesis of the material and to partial Li cation incorporation into the crystal structure of the host compound. The optimal modifier concentration is 1–2 wt %.