# Metallization of warm dense SiO$_2$ studied by XANES spectroscopy

Abstract : We investigate the evolution of the electronic structure of fused silica in a dense plasma regime using time-resolved x-ray absorption spectroscopy. We use a nanosecond (ns) laser beam to generate a strong uniform shock wave in the sample and a picosecond (ps) pulse to produce a broadband x-ray source near the Si $K$ edge. By varying the delay between the two laser beams and the intensity of the ns beam, we explore a large thermodynamical domain with densities varying from 1 to 5 g/cm$^3$ and temperatures up to 5 eV. In contrast to normal conditions where silica is a well-known insulator with a wide band gap of 8.9 eV, we find that shocked silica exhibits a pseudogap as a semimetal throughout this thermodynamical domain. This is in quantitative agreement with density functional theory predictions performed using the generalized gradient approximation.
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https://hal.archives-ouvertes.fr/hal-01561842
Contributor : Fabien Dorchies Connect in order to contact the contributor
Submitted on : Wednesday, January 12, 2022 - 4:45:26 PM
Last modification on : Friday, January 14, 2022 - 3:36:11 AM

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denoeud2014.pdf
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### Citation

A. Denoeud, A. Benuzzi-Mounaix, A. Ravasio, F. Dorchies, P. M. Leguay, et al.. Metallization of warm dense SiO$_2$ studied by XANES spectroscopy. Physical Review Letters, American Physical Society, 2014, 113 (11), pp.116404. ⟨10.1103/PhysRevLett.113.116404⟩. ⟨hal-01561842⟩

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