Structural And Functional Investigation Of Fe/Pb/Zr-co-doped Barium Titanate Ceramics: From Theory To The Experiment

Abstract

Mixtures of high purity powders of 50 mass% Fe, 4 mass% Pb, 3 mass% Zr and 43 mass% BaTiO3 were activated in a rotary ball mill for durations ranging from 30 min to 300 min; samples were then sintered in the air atmosphere for 2 hours at 1200 °C. Crystal structure prediction has been performed using Bond ValenceCalculation (BVC) method.Moreover, theoretical stability of theperovskite structure for synthesized and calculated Fe/Pb/Zr-codoped barium titanatecompounds has been investigated using the Goldschmidttolerance factor (Gt) and global instability index (GII).It was observed that magnetization of the system decreased after the sintering, with the most dramatic drop of 90.11% belonging to the sample activated for 150 min. In comparison with initial powders, X-ray powder diffractiondata confirmed the presence of newphases of BaFe12O19 and Ba1.696Ti0.228O3 in sintered samples. Utilizing the field emission scanning electron microscopy (FESEM), it was found that with the increase of activation time the morphology of the samples progressed from irregural, spherical grains to mostly rod-like ones. Energy dispersive X-ray (EDX) analysis identified the presence of Pb and Zr occupying the same locations on the surface of sintered samples, whilst Fe was uniformly deployed regardless of the activation time.