Octahedral conversion of a-SiO2-host matrix by pulsed ion implantation

This is the abstract. The results of measurements of X-ray photoelectron spectra (XPS) of a-SiO2-host material after pulsed implantation with [Mn+] and [Co+, Mn+]-ions as well as DFT-calculations are presented. The low-energy shift is found in XPS Si 2p and O 1s core-levels of single [Mn+] and dual [Co+, Mn+] pulsed ion-implanted a-SiO2 (E = 30 keV, D = 2*10^17 cm^-2) with respect to those of untreated a-SiO2.The similar changes are found in XPS Si 2p and O 1s of stishovite compared to those of quartz. This means that the pulsed ion-implantation induces the local high pressure effect which leads to an appearance of SiO6-structural units in alpha-SiO2 host, forming "stishovite-like" local atomic structure. This process can be described within electronic bonding transition from the four-fold "quartz-like" to six-fold "stishovite-like" high-pressure phase in SiO2 host-matrix. It is found that such octahedral conversion depends on the fluence and starts with doses higher than D = 3*10^16 cm^-2.Comment: 15 pages, 6 figures, 1 table, accepted in phys. stat. solidi (b

Cathodoluminescence of Quartz, Silica and Thin Amorphous SiO₂ Layers

ABSTRACTCathodoluminescence and its temperature-dose behaviour of different modifications of SiO2 are presented. The detected luminescence bands are attributed to three optical active luminescence centers: the twofold coordinated silicon center (=Si:), the non-bridging oxygen hole center (NBOHC) and the self-trapped exciton (STE). The experiments are correlated with infrared absorption measurements. Existing structural models are discussed with reference to our results.</jats:p

Digital Cultural Heritage Twins: New Tools for a Complete Fruition of the Cultural Heritage Entities

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