Evaluation of Optical and Acoustical Properties of Ba1−xSrxTiO3 Thin Film Material Library via Conjugation of Picosecond Laser Ultrasonics with X-ray Diffraction, Energy Dispersive Spectroscopy, Electron Probe Micro Analysis, Scanning Electron and Atomic Force Microscopies

Abstract

Wide-range continuous spatial variation of the film composition in lateral compositionally graded epitaxial films requires the development of high throughput measurement techniques for their local and non-destructive characterization with the highest possible spatial resolution. Here we report on the first application of the picosecond laser ultrasonics (PLU) technique for the evaluation of acoustical and optical parameters of lateral compositionally graded film, the Ba1−xSrxTiO3 (0 ≤ x ≤ 1) material library. The film was not dedicatedly prepared for its opto-acousto-optic evaluation by PLU, exhibiting significant lateral variations in thickness and surface roughness. Therefore, the achieved measurements of the sound velocity and of the optical refractive index, and characterization of the surface roughness confirm the robustness of the PLU technique for thin film evaluation. We hope that the first measurements of the acoustical and optical properties of epitaxial grown Ba1−xSrxTiO3 (0 ≤ x ≤ 1) by PLU technique accomplished here provide the parameters required for more extended predictive design of the phononic, photonic and phoxonic mirrors and cavities with superior properties/functionalities for novel multifunctional nanodevices.

Phonon dynamics in novel materials and hybrid structures

“…These arise from the interferences between the probe light reflected by the sample's stationary interfaces and that scattered by the propagating longitudinal acoustic wave in the structure. [19][20][21] This frequency value aligns well with the estimates for the refractive index in STO and for the 840 nm wavelength of the probe laser beam. The mode which is inhibited or enhanced within the designated stop band range of the mirror superlattice, depending on the thickness of the Ni layer, can be attributed to the confined mode in the Ni spacer of the hybrid cavity structure.…”

“…The lower frequency mode, independent of the thickness of Ni, located at 45 GHz in the frequency spectrum corresponds to Brillouin oscillations in the structure. These arise from the interferences between the probe light reflected by the sample's stationary interfaces and that scattered by the propagating longitudinal acoustic wave in the structure [19][20][21]. This frequency value aligns well with the estimates for the refractive index in STO and for the 840 nm wavelength of the probe laser beam.…”

Structural and dielectric characterization of synthesized nano-BSTO/PVDF composites for smart sensor applications

“…14 These materials may be utilized in a variety of contexts, including as parts of microwave and other device capacitors. 15 More recent research on Ba 1− x Sr x TiO 3 synthesized by the sol–gel method has also revealed that the Sr content affects the crystalline structure, grain size, densification, thermal conductivity, and compressive strength. 16…”

“…14 These materials may be utilized in a variety of contexts, including as parts of microwave and other device capacitors. 15 More recent research on Ba 1Àx Sr x TiO 3 synthesized by the sol-gel method has also revealed that the Sr content affects the crystalline structure, grain size, densification, thermal conductivity, and compressive strength. 16 Polyvinylidene fluoride, also known as PVDF, is a widely studied electroactive polymer due to its versatility in a variety of applications, including energy generation, bio-materials, sensors, and actuators.…”

Impact of High Heat Treatment on Ferroelectric Materials Properties: Ba1−xSrxTiO3 as a Model

“…1 When an electric field is applied, ferroelectric characteristics exhibit spontaneous polarisation even after the field is removed. 2 Furthermore, those materials have a hysteresis loop as a function of an electric field, meaning that the materials are used as energy storage. This process depends on factors such as the type of raw materials used, preparation conditions, and high voltage as the source for the electric field.…”