A Comparative Analysis of BaTiO 3 /(Ba,Sr)TiO 3 and BaTiO 3 /(Ba,Sr)TiO 3 /SrTiO 3 Artificial Superlattices via Raman Spectroscopy

摘要

BaTiO 3 /Ba 50 Sr 50 TiO 3 and BaTiO 3 /Ba 50 Sr 50 TiO 3 /SrTiO 3 superlattices are characterized via Raman spectroscopy. Special attention is paid to a comprehensive analysis of their polarized Raman spectra, especially, within a soft mode ( E (1 TO )) range. The shift of E (1 TO ) soft mode is found to be more pronounced for BaTiO 3 /Ba 50 Sr 50 TiO 3 /SrTiO 3 sample than for BaTiO 3 /Ba 50 Sr 50 TiO 3 , presumably owing to stronger 2D compression of BT layers and abruptly increased temperature of transition from ferroelectric to paraelectric phase.