Five Layers Aurivillius Phases Pb2-xBi4+xTi5-xMnxO18: Synthesis, Structure, Relaxor Ferroelectric and Magnetic Properties

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Synthesis of five layers Aurivillius phases, Pb 2-x Bi 4+x Ti 5-x Mn x O 18 (0  x  1) were carried out by molten salts method using eutectic mixture of Na 2 SO 4 /K 2 SO 4 salts (1:1 molar ratio) as the flux.The samples were characterized by X-ray diffraction powder and refined by Le Bail technique.The refinement results revealed that the samples with composition x = 0, 0.2, 0.4, and 0.6 formed five layers Aurivillius with the space group B2cb; however, the samples with x = 0.4 and 0.6 contained impurity as BiMnO 3 and the additional phase of four layers Aurivillius (PbBi 4 Ti 4 O 15 ) was also observed for x = 0.6.The samples with x = 0.8 and 1 resulted in two phases: four layers Aurivillius and BiMnO 3 .The dielectric properties of the Pb 2-x Bi 4+x Ti 5-x Mn x O 18 show broad peaks with the temperature of the maximum of the dielectric constant (T m ) at temperature of 295, 295, 304, and 343C at a frequency of 2 MHz for x = 0, 0.2, 0.4, and 0.6, respectively.The T m of these samples is shift to the left with decreasing frequency as indication of relaxor ferroelectric behavior.The samples with x = 0.8 and 1 show anomaly at 514C and 551C which correspond to the transition phase of four layers Aurivillius.Magnetic properties for all samples containing Mn are paramagnetic.

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