Revisiting the Entangled Chains of Polymer in the Carbyne Model

The Monte Carlo carbyne model is modified to investigate the glass transition of the simplified polymer chains. The stochastic bombardment between monomers is monitored by Metropolis algorithm with the help of the consideration of hard potential while the mobility of monomers is governed by its mass, scattering rate, and temperature. Our model is capable to show that the glass transition temperature reduces with decreasing film thickness and the formation of critical voids in the thinner polymer contributing to the glass transition that is much easier than the bulk polymer.     

Photoluminescence of implantation-induced defects in SiO2:Pb+ glasses

The luminescence of quartz glass with implanted Pb⁺ ions is investigated by time-resolved photoluminescence spectroscopy under synchrotron excitation. It is established that the glass layer modified with ions represents a microheterogeneous medium with a variable content of implanted ions predominantly in the form of Pb²⁺. Three different types of emission centers are detected that are created by radiation-induced defects of the SiO₂ matrix and localized electronic states of the amorphous lead-silicate phase.     

Interference effects in the UV(VUV)‐excited luminescence spectroscopy of thin dielectric films

The problem of exciting UV and VUV light interference affecting experimental photoluminescence excitation spectra is analysed for the case of thin transparent films containing arbitrarily distributed emission centres. A numerical technique and supplied software aimed at modelling the phenomenon and correcting the distorted spectra are proposed. Successful restoration results of the experimental synchrotron data for ion‐implanted silica films show that the suggested method has high potential.     

Electronic Work Function of Carbon Nanocomposite Films According to Vacuum and Atmospheric Photoemission

Technical Physics - Using the methods of optically stimulated electron emission (OSEE) and ambient pressure photoemission spectroscopy (APS), the energy characteristics of carbyne-containing films...     

Urbach rule in photoelectron emission from surface states of low-sized silica

Spectral and temperature dependences of photoelectron emission from surface (interface) states of SiO₂ films and nanocompacts in the near UV region were studied. They were interpreted in terms of ‘frozen phonons’ conception and modified three-stage electron emission model. The electron emission analog of optical Urbach rule for low-sized silica was proposed. Optical absorption stage was recognized as the dominant phase of electron emission process. The structure and energy parameters of studied samples were obtained. It was revealed that thin and thick SiO₂ films have similar structure parameters while their effective potential barriers differ because of different electron transport conditions. High value of static structural disorder in compacted SiO₂ nanopowders is attributed to peculiarities of their ultradispersed structure.