Effect of Vanadium on Structural and ElectricalProperties of Pb(Fe_(0.5)Nb_(0.5))O_3Ceramics

摘要

Pb(Fe_(0.5)Nb_(0.5)O_3where ferroelectrics and magnetic order coexistexhibits has very high dielectric constant and therefore it is an attractivecandidate for multilayer capacitors. In view of the above, we have synthesizedPolycrystalline samples of Pb (Fe_(0.5)Nb_(0.5-x)V_x)O_3,X=-0,0.5,0.1,0.15 by a hightemperature solid-state reaction technique at 800 ° C. Preliminary structuralanalysis suggests that the compounds have been formed in single-phasemonoclinic crystal system. Scanning electron micrographs of the compoundsshow that the grains are uniformly and densely distributed over the entiresurface of the sample. Detailed studies of die-electric properties (die-electricconstant and tangent loss) as a function of frequency (103-106 Hz) andtemperature (30- 330C) suggest that the compounds undergo ferroelectric-paraelectric phase transition with lowering in transition temperature onincreasing vanadium content. Electrical parameters (impedance andconductivity) of all the compounds were measured using complex impedancespectroscopy (CIS) technique in the above said temperature and frequencyrange. The complex impedance plots show that there is only bulk (grain)contribution in the compounds in the mentioned temperature range. The ac anddc conductivities were found to increase on increasing temperature suggestingNTCR behavior of the materials.