SINTESIS SENYAWA AURIVILLIUS LAPIS EMPAT CaBi4-xLaxTi4O15 DENGAN MENGGUNAKAN METODE LELEHAN GARAM

Aurivillius phase is a type of metal oxide compound with general formula [Bi2O2]2+ [An-1BnO3n+1]2- consisting of perovskite layer and bismuth layer in a single phase. Aurivillis phase with formula CaBi4Ti4O15 has ferroelectric properties and very potensial to be developed as reference in the advance material for data-storage. The modification of four layers CaBi4-xLaxTi4O15 (x = 0; 0.5; 1.0; 1.5 and 2.0) Aurivillius phase was synthesized using molten salt method. Precursors were weighted stoichiometically and grinded homogeneously with the eutectic mixture of Na2SO4/ K2SO4 salts. The mixture of precursors and salts were heated at temperatures of 750 C and 850 C for 10 h and 950 C for 5 h. The products were then characterized by X-Ray Diffractometer (XRD) and Scanning Electron Microscope (SEM). XRD data were refined by Rietica program with Le Bail method. Refinement results revealed the formation of four layers CaBi4-xLaxTi4O15 for all compositions. The single phase of Aurivillius with A21am space group was shown by the x ≤1.5. The orthorhombic of the single phase of Aurivillius decrease as the increasing of La3+ concentration in the sample. The surface analysis by SEM showed that the surface was plate-like in accordance with the unique feature of Aurivillius phase. Raman spectroscopic measurements show a peak shift for each addition of La3+ variation. Measurement of dielectric properties at room temperature shows an increase in dielectric constant value with an increase of La3+ to x = 1.0. Keywords: Aurivillius phase, molten salts, ferroelectric, Le Bail method