Raman Spectra of Sr{sub}(m-3)Bi{sub}4Ti{sub}mO{sub}(3m+3) Thin Films

摘要

A series of bismuth layer-structured ferroelectrics thin films Sr{sub}(m-3)Bi{sub}4Ti{sub}mO{sub}(3m+3)(m=3, 4, 5, and 6) were deposited by pulsed laser deposition (PLD) on (001) LaAlO{sub}3 single crystal substrate. XRD and Raman studies have been performed. The more sensitive Raman spectra lead to a different understanding on the layer structure of Sr{sub}3Bi{sub}4Ti{sub}6O{sub}21 from XRD. This can be attributed to the lager c-axis constant of Sr{sub}3Bi{sub}4Ti{sub}6O{sub}21 due to more layers. More layers lead to increasing disorder in the local scale of the average grain.