Study of A-site doping of SrBi4Ti4O15Bi-layered compounds using micro-Raman spectroscopy

The temperature-dependent Raman spectra of Mg- and La-doped SrBi4Ti4O15 (SBT) were studied in the range 40-590 degrees C. A quantum chemistry calculation was employed to estimate these two substitution states. It was found that A-site doping in this study not only caused multiplicative substitution states, but also the Raman spectra changed with the substitution amount. In a La-doped perovskite-like layer, La would occupy the Bi site when x > 0.10 and the 314 and 550 cm(-1) modes related to the rotating and tilting of the TiO6 octahedron firstly became wide and then became sharp. With the increase of the substitution amount, both substitution states of Mg-doped SBT lead to the widening of 270 and 520 cm(-1) peaks.