Dielectric and ferroelectric properties of lead indium niobate ceramic prepared by wolframite method

The dielectric and ferroelectric properties of lead indium niobate (Pb(In1/2Nb1/2)O-3, PIN) ceramic prepared by an oxide-mixing method via wolframite route were investigated. The 98.5% perovskite fine-grained PIN ceramics with average grain sizes of 1-2 mu m were obtained by sintering at 1050 degrees C for 2 h. The dielectric properties of the PIN were of relaxor ferroelectric behavior with temperature of dielectric maximum (T-m) similar to 53 degrees C and dielectric constant (epsilon(r)) similar to 4300 (at 1 kHz). The P-E hysteresis loop measurements at various temperatures showed that the ferroelectric properties of the PIN ceramic changed gradually from the paraelectric behavior at temperature above T-m to slim-loop type relaxor behavior at temperature below T-m. Moreover, the P-E loop became more open at temperatures much lower than T-m. At -25 degrees C, the maximum polarization is found to be 8 mu m/cm(2) at a field of 30 kV/cm, with P-r value of 2.5 mu m/cm(2) and E-c of +7.5 kV/cm. (C) 2007 Elsevier Ltd and Techna Group S.r.l. All rights reserved.