New insights from Raman and IR spectroscopy into the metal-insulator transition of YHx switchable mirrors

Autor:	A.-M. Racu, M. Rode, S. Weber, J. Schoenes
Rok vydání:	2007
Předmět:	Chemistry Phonon Mechanical Engineering Metals and Alloys Electronic structure Activation energy Inelastic scattering symbols.namesake Mechanics of Materials Electron excitation Materials Chemistry symbols Atomic physics Spectroscopy Electronic band structure Raman spectroscopy
Zdroj:	Journal of Alloys and Compounds. :562-566
ISSN:	0925-8388
DOI:	10.1016/j.jallcom.2006.12.141
Popis:	The important recent contributions of elastic and inelastic light scattering to our understanding of the electronic structure and the metal-insulator transition of the switchable-mirror prototype material YH x will be reviewed. In particular, we will discuss the striking broadening with increasing temperature of one single Raman line, corresponding to a breathing mode of Y atoms surrounding a hydrogen site. It is shown that the extra broadening is due to electron–phonon coupling and that it follows an Arrhenius law with an activation energy of 0.09 eV. A close inspection of our IR spectra shows at the same energy an absorption line with an anomalous temperature dependence, which results from the overlap of a phonon and an electron excitation. This energy is assigned to the activation of electrons trapped in hydrogen vacancies, corroborating the correlated electron models for the electronic structure.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::caf5e43a216d5d5bc796164070073752 https://doi.org/10.1016/j.jallcom.2006.12.141 Zobrazit plný text záznamu Full Text from ScienceDirect