Aurivillius type M0.5Bi4.5-xSmxTi4O15 (x = 0 and 0.5, M= Na or K) thin films were prepared on Pt(111)/Ti/Si/SiO2(100) substrates by using a chemical solution deposition method. Fabricated thin films were crystallized in pure Aurivillius phase orthorhombic structures, which were confirmed by X-ray diffraction and Raman spectroscopy studies. The use of Sm3+-ions for doping purposes results in remarkable improvements in electrical and ferroelectric properties of the M0.5Bi4.5-xSmxTi4O15 thin films. A study of the ferroelectric hysteresis loops enabled the remnant polarization (2P r) and coercive field (2E c) values for the Na0.5Bi4Sm0.5Ti4O15 and the K0.5Bi4Sm0.5Ti4O15 thin films to be measured as 34.4 mC/cm2 and 220 kV/cm at an applied electric field of 475 kV/cm and 36.0 mC/cm2 and 103 kV/cm at 231 kV/cm, respectively. The 2P r values measured for the thin films doped with Sm3+-ions were much larger than those of the un-doped thin films. The 2E c values of the M0.5Bi4.5-xSmxTi4O15 thin films were also drastically lowered. Furthermore, low leakage current densities were measured for the M0.5Bi4.5-xSmxTi4O15 thin films.

Keywords: Thin films, Electrical properties, Ferroelectric materials, X-ray methods.