Suchergebnisse

In this project, a structural and vibrational characterization under high-pressure of the In2Se3 compound will be carried out using the techniques of X-ray diffraction and Raman spectroscopy, respectively. It will be addressed some open issues related to its characterization under pressure. A literature review of all studies conducted to date using temperature and high pressure will be held in order to show all its polytypes, applications and technological interest. ; En este proyecto, el compuesto In2Se3 será caracterizado bajo alta presión tanto desde el punto de vista estructural como vibracional utilizando las técnicas de difracción de rayos X y la espectroscopia Raman, respectivamente. Serán abordadas algunas cuestiones abiertas relacionadas con su caracterización bajo presión. Una revisión bibliográfica de todos los estudios realizados hasta la fecha usando la temperatura como la alta presión será llevado a cabo con el fin de mostrar todos los sus posibles politipos, aplicaciones y su interés tecnológico. ; Gallego Parra, S. (2017). Caracterización estructural y vibracional del compuesto In2Se3 y sus aplicaciones. http://hdl.handle.net/10251/93472 ; TFGM

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Inorganic Chemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://doi.org/10.1021/acs.inorgchem.8b00778 ; [EN] alpha(R)-In2Se3 has been experimentally and theoretically studied under compression at room temperature by means of X-ray diffraction and Raman scattering measurements as well as by ab initio total-energy and lattice-dynamics calculations. Our study has confirmed the alpha (R3m) -> beta' (C2/m) ? beta (R (3) over barm) sequence of pressure-induced phase transitions and has allowed us to understand the mechanism of the monoclinic C2/m to rhombohedral R (3) over barm phase transition. The monoclinic C2/m phase enhances its symmetry gradually until a complete transformation to the rhombohedral R (3) over barm structure is attained above 10-12 GPa. The second-order character of this transition is the reason for the discordance in previous measurements. The comparison of Raman measurements and lattice-dynamics calculations has allowed us to tentatively assign most of the Raman-active modes of the three phases. The comparison of experimental results and simulations has helped to distinguish between the different phases of In2Se3 and resolve current controversies. ; The authors acknowledge financial support from Spanish government MINECO, the Spanish Agencia Estatal de Investigacion (AEI), and Fondo Europeo de Desarrollo Regional (FEDER) under Grants No. MAT2016-75586-C4-1/2/3-P and MAT2015-71070-REDC. ; Vilaplana Cerda, RI.; Gallego-Parra, S.; Jorge-Montero, A.; Rodríguez-Hernández, P.; Muñoz, A.; Errandonea, D.; Segura, A. (2018). Experimental and Theoretical Studies on alfa-In2Se3 at High Pressure. Inorganic Chemistry. 57:8241-8252. https://doi.org/10.1021/acs.inorgchem.8b00778 ; S ; 8241 ; 8252 ; 57