Ferroelectric Properties of $Ba2Bi4Ti5O18$ Doped with $Pb2+,$ $Al3+,$ $Ga3+,$ $In3+,$ $Ta5+$ Aurivillius Phases

In recent years, bismuth layer structured ferroelectrics (BLSFs) have been given much attention because some materials, such as $Ba2Bi4Ti5O18,$ are excellent candidate materials for nonvolatile ferroelectric random access memory (FRAM) applications. BLSFs are also better candidates because of their higher Curie points. Recently, we have carried out computer simulation in atomic scale in order to predict the energies associated with the accommodation of aliovalent and isovalent dopants (⁠$Pb2+,$ $Al3+,$ $Ga3+,$ $In3+,$ $Ta5+$⁠) in the Aurivillius structure of $Ba2Bi4Ti5O18.$ In this work, the predicted stable phases were synthesized using solid state reactions and their products then were characterized using powder X‐ray diffraction method. The cell parameters were determined using Rietveld refinement in orthorhombic system with space group of B2cb. The cell parameters for $Ba2Bi4Ti5O18$ doped with $Pb2+,$ $Al3+,$ $Ga3+,$ $In3+,$ $Ta5+$ were $a = 5.5006(6)$ $b = 5.4990(5)$ $c = 50.5440(7) Å;$ $a = 5.5012(4)$ $b = 5.4986(8)$ $c = 50.5449(7) Å;$ $a = 5.5006(3)$ $b = 5.4999(3)$ $c = 50.5437(9) Å;$ $a = 5.5007(4)$ $b = 5.4989(7)$ $c = 50.5446(6) Å;$ and $a = 5.5000(5)$ $b = 5.4995(8)$ $c = 50.5436(6) Å.$ Results from the ferroelectric properties measurement for $Ba2Bi4Ti5O18$ doped with $Pb2+,$ $Al3+,$ $Ga3+,$ $In3+,$ $Ta5+$ were $Pr = 16.7 μC/cm2,$ $Ec = 35.1 kV/cm;$ $Pr = 15.9 μC/cm2,$ $Ec = 33.8 kV/cm;$ $Pr = 15.6 μC/cm2,$ $Ec = 34.2 kV/cm;$ $Pr = 15.3 μC/cm2,$ $Ec = 34.0 kV/cm;$ $Pr = 16.9 μC/cm2,$ $Ec = 35.6 kV/cm.$