Experimental and theoretical study of b2x3 sesquichalcogenides under extreme conditions
- Autores: Samuel Gallego Parra
- Directores de la Tesis: Oscar Gomis Hilario (dir. tes.), Rosario Isabel Vilaplana Cerdá (dir. tes.), Francisco Javier Manjón Herrera (tut. tes.)
- Lectura: En la Universitat Politècnica de València ( España ) en 2022
- Idioma: español
- Tribunal Calificador de la Tesis: Bernabé Marí Soucase (presid.), Lourdes Gracia Edo (secret.), Gaston Garbarino (voc.)
- Programa de doctorado: Programa de Doctorado en Diseño, Fabricación y Gestión de Proyectos Industriales por la Universitat Politècnica de València
- Materias:
- Enlaces
- Tesis en acceso abierto en: RiuNet
- Resumen
B2X3 sesquichalcogenides (A = Al, Ga and In, X = S, Se y Te) have received special attention along last years, with great emphasis in tailor them to attain new structures to novel properties, driving them in a huge number of applications. Although high/low temperature or varying chemical composition have been extensively used to modify and obtain new structures, high pressure is gaining relevance as an alternative way to synthetised new materials. To reach such pressures and additionally high/low temperatures, diamond anvil cells are used. Many experimental techniques can be coupled to these tools to study matter under extreme conditions (Raman and IR spectroscopy, X-ray diffraction and absorption, optical absorption, and resistivity measurements, among others). Additionally, computational simulations are used to give further support to the experimental results.
Despite the several existing works devoted to the behaviour under pressure of this family, controversial results have been reported. The most studied of these sesquichalcogenides have been Ga2S3, In2S3 and In2Se3. The aim of this thesis is to revisit the pressure effects by means of Raman spectroscopy and X-ray diffraction, with the help of computational simulations, for the purpose of clarify the results published earlier.
The current thesis contains the four articles published in indexed journals, resulting from the study of these three sesquichalcogenides. Such articles shed light to the pressure behavior of these compounds, their vibrational and structural properties under pressure, pressure-induced phase transitions and the mechanisms behind them and characterize such high-pressure phases. With these works, we pursue not only a depth understanding of the pressure behavior of these sesquichalcogenides, but boost future high-pressure works on the rest of the family and other similar compounds, as AB2X4 with spinel structure and ordered vacancies.
