The MRO-accompanied modes of Re-implantation into SiO 2-host matrix: XPS and DFT based scenarios

摘要

AbstractThe following scenarios of Re-embedding into SiO2-host by pulsed Re-implantation were derived and discussed after XPS-and-DFT electronic structure qualification: (i) low Re-impurity concentration mode → the formation of combined substitutional and interstitial impurities with Re2O7-like atomic and electronic structures in the vicinity of oxygen vacancies; (ii) high Re-impurity concentration mode → the fabrication of interstitial Re-metal clusters with the accompanied formation of ReO2-like atomic structures and (iii) an intermediate transient mode with Re-impurity concentration increase, when the precursors of interstitial defect clusters are appeared and growing in the host-matrix structure occur. An amplification regime of Re-metal contribution majority to the final Valence Band structure was found as one of the sequences of intermediate transient mode. It was shown that most of the qualified and discussed modes were accompanied by the MRO (middle range ordering) distortions in the initial oxygen subnetwork of thea-SiO2host-matrix because of the appeared mixed defect configurations.Highlights?Co-existence of multiple local electronic configurations of Re-impurities in SiO2.?Formation of substitutional and interstitial defects in the form of clustering.?At low Re-concentrations the Re2O7-like configurations are formed.?An increasing of Re-concentrations provides the conversion to ReO2-like structures.?Metallic Re-loss effect in SiO2t also observed at high concentration of impurities.]]>