Five layers Aurivillius phases Pb2-xBi4+xTi5-xMnxO18: Synthesis,structure,relaxor ferroelectric and magnetic properties

Synthesis of five layers aurivillius phases,pb2-xbi4+xti5-xmnxo18 (0 ≤ x ≤ 1) were carried out by molten salts method using eutectic mixture of na2so4/k2so4 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 bimno3 and the additional phase of four layers aurivillius (pbbi4ti4o15) was also observed for x = 0.6. the samples with x = 0.8 and 1 resulted in two phases: four layers aurivillius and bimno3. the dielectric properties of the pb2-xbi4+xti5-xmnxo18 show broad peaks with the temperature of the maximum of the dielectric constant (tm) 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 tm 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.