Effect of Ti Doping on Structural and ElectricalProperties of Ba(Fe(0.5)Nb.(0.5))O3Ceramic

摘要

Polycrystalline samples of Ba(Fe(1-x)Ti(2x)Nb(1-x)(0.5)O3(BF-EN) with x= 0, 0.1, 0.2 havebeen synthesized using a high-temperature solid-state reaction technique. The X-ray diffractionof the sample (x =0) at room temperature shows a monoclinic phase. When the doped contentsof Ti are over 10 mole% the structure changes from monoclinic to tetragonal. Scanning electronmicrographs of the compounds show that grains are uniformly and densely distributed over theentire surface of the sample. The complex impedance plots show that there is only bulk (grain)contribution in the compounds in the said temperature range, and is of non-Debye type ofrelaxation. Bulk resistance of the material has been observed to be concentration dependent.Conductivity analysis indicates that ac/dc conductivity of the materials increases with increase intemperature. It shows a typical negative temperature coefficient of resistance (NTCR) behaviourlike a semiconductor. The conductivity has been found to decrease on Ti doping.