Premium
Permanent Ge Coordination Change Induced by Pressure in La 2 O 3 –B 2 O 3 –GeO 2 Glass
Author(s) -
CoussaSimon Camille,
Martinet Christine,
De Ligny Dominique,
Deschamps Thierry,
Trapananti Angela,
Champag Bernard
Publication year - 2010
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2010.03797.x
Subject(s) - germanium , absorption spectroscopy , coordination number , diamond anvil cell , ambient pressure , absorption (acoustics) , crystallography , spectral line , absorption edge , x ray crystallography , x ray absorption spectroscopy , spectroscopy , analytical chemistry (journal) , chemistry , materials science , mineralogy , high pressure , diffraction , thermodynamics , optics , silicon , physics , ion , optoelectronics , organic chemistry , chromatography , quantum mechanics , astronomy , band gap , composite material
In this study, we report the results of an in situ X‐ray absorption spectroscopy investigation of the La 2 O 3 –B 2 O 3 –GeO 2 (LBG) glass compressed in a diamond anvil cell until 17 GPa at ambient temperature. A pressure‐induced coordination change of germanium from fourfold to sixfold is shown here. The analysis of Ge K‐edge X‐ray absorption near‐edge structure spectra supports a model of mixing of fourfold and sixfold coordinated Ge sites during the compression/decompression cycle. This transformation proves to be irreversible: about 25% of sixfold coordinated Ge still exists at ambient pressure. This phenomenon underlines a polymorphism property of the LBG glass, whose origin lies in the complexity of composition.