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Five Layers Aurivillius Phases Pb2-xBi4+xTi5-xMnxO18: Synthesis, Structure, Relaxor Ferroelectric and Magnetic Properties
Zulhadjri1, B. Prijamboedi1, A.A. Nugroho2, N. Mufti3 & Ismunandar1,*
1Inorganic and Physical Chemistry Group, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha No. 10 Bandung, Indonesia 2Magnetic and Photonic Physics Research-Group, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha No. 10 Bandung, Indonesia 3Physics Department, Universitas Negeri Malang, Jl. Surabaya 6 Malang 65145, Indonesia Email: ismu@chem.itb.ac.id
Abstract. 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 anomaly (Tm) at temperature 295 °C, 295 °C, 304 °C, and 343 °C at frequency 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.
Keywords: five layers aurivillius phase; molten-salts; relaxor ferroelectric; paramagnetic.
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