Phase transition of TiO2 thin films detected by the pulsed laser photoacoustic technique

Detection of zinc blende phase by the pulsed laser photoacoustic technique in ZnO thin films deposited via pulsed laser deposition

“…When pulsed laser sources are used to produce the PA effect, the absorption of each pulse in the medium leads the generation of a broadband thermoelastic pressure wave that propagates through the medium with its respective speed of sound. Moreover, by using pulsed lasers with temporal width in the range of nanoseconds as light sources, and piezoelectric ceramics as sensors, an improvement in the signal-noise relation has been achieved (among the acoustic signal measured with piezoelectric and the acoustic aerial and electrical sound that can be introduced into the measurement) [18,25] The main characteristics of the acoustic waves propagating through a material depend on the crystalline structure of the medium. Thereby, it is possible to detect structural changes in the studied material under controlled temperature increase.…”

“…One technique that has proven to be useful for analyzing the structural changes in different kinds of materials is pulsed laser photoacoustic (PLPA), whose main characteristic is that it provides of high sensitivity to detect minor phases [18][19][20][21].…”

Thermomechanical and Photophysical Properties of Crystal-Violet-Dye/H2O Based Dissolutions via the Pulsed Laser Photoacoustic Technique

“…In a typical PLPA experiment, the acousticwaves travel at the characteristic speed of sound of the excited material to reach a coupled piezoelectric detector; this allows the mechanical-electrical experimental interface to collect the PLPA-data from the sample on a digital oscilloscope for subsequent numerical analyses. The experimental simplicity to obtain photoacoustic signals has led to the development of several PLPA-based measurement devices which are commonly used for the accurate evaluation of thermal and optical properties of different materials such as organic and inorganic crystals, semiconductor, and polymer systems [2][3][4][5][6][7][8][9]. In summary, several physical and structural material characteristics can be efficiently studied by means of diverse PLPA-based techniques and the adequate data analysis thereof.…”