Detecting Non-bridging Oxygens: Non-Resonant Inelastic X-ray Scattering in Crystalline Lithium Borates
Résumé
Probing the local environment of low-Z elements, such as oxygen, is ofgreat interest for understanding the atomic-scale behavior in materials, but it requiresexperimental techniques allowing it to work with versatile sample environments. In thispaper, the local environment of lithium borate crystals is investigated using nonresonantinelastic X-ray scattering (NRIXS) at energy losses corresponding to theoxygen K-edge. Large variations of the spectral features are observed close to the edgeonset in the 535−540 eV energy range when varying the Li2O content. Calculationsallow identification of contributions associated with bridging oxygen (BO) and nonbridgingoxygen (NBO) atoms. The main result resides in the observed core-level shiftof about 1.7 eV in the spectral signatures of the BO and NBO. The clear signature at535 eV in the O K-edge NRXIS spectrum is thus an original way to probe the presence of NBOs in borates, with the greatadvantage of making possible the use of complex environments such as a high-pressure cell or high-temperature device for in situmeasurements