“…Moreover, according to the Raman spectroscopy, the strain in BT constituents seems to induce the monoclinic phase in them, decreasing to a large extent the disorder of Ti 4+ ions, which suggests the appearance of a polar phase in BZ layers, as follows from the drastically upshifted (by seven times) low-frequency E(1TO) soft mode and the unchanged A1(2TO) soft-mode component. erefore, in comparison with epitaxial structures with varying stoichiometry in one of the constituent layers [11][12][13], the design of superlattices with asymmetric constituent thickness at a constant modulation period allows one to achieve a much more drastic transformation of E(1TO) soft modes (by seven times in this study) over against the parent BT film. In this respect, the fabrication of superlattices with a predefined composition enables one to achieve the structures with tunable properties, which ensures their proper application.…”