Redistribution of indium implanted in silicon due to thermal treatment and swift heavy ion irradiation

Silicon layers of 150 nm thickness supersaturated with indium up to ≈5 at% were prepared by multiple energy ion implantation. A redistribution of the implanted impurities caused by post-implantation annealing and following irradiation with swift Bi ions has been observed by means of Rutherford backscattering spectrometry in channelling configuration (RBS/C). It is demonstrated by TEM that the thermal decomposition of the supersaturated Si〈In〉 solution is accompanied by polycrystalline recrystallisation of amorphous silicon, precipitation of the second phase (In) both within the implanted layer and on the surface, as well as by impurity redistribution. The main features of the structure transformation under the influence of the Bi ion irradiation are discussed.     

Cyclic degradation of material in vehicle components

A nonstandard approach to the fatigue strength of materials and structures is proposed, within the framework of the complete-diagram method. The use of the cyclic-degradation model in calculating the life of vehicle components is illustrated. In supercritical cycling, linear summation of the damage is possible in some situations.     

On the room-temperature annealing of cryogenically rolled copper

The electron-backscatter-diffraction (EBSD) technique was applied to investigate room-temperature annealing processes in cryogenically rolled copper during long-term (∼1.5 years) storage at ambient temperature. Static recrystallization appeared to be nucleated as result of both grain-boundary bulging and recovery. A bimodal recrystallized grain size distribution appeared to be a result of these two competing mechanisms. The ultra-fine grain copper produced via cryogenic deformation was deduced to be prone to abnormal grain growth after long static storage at room-temperature.     

Analysis of fiber probes of scanning near-field optical microscope by field emission microscopy.

It is shown that field emission microscopy and related methods can be used to analyze the metal coated fiber tips, which nowadays are the most frequently used sensor for the scanning near-field optical microscopy (SNOM). Metal free and thus non field-emitting aperture for the light transmission on the tip apex can be directly seen and its parameters can be measured, which is very important for the interpretation of SNOM data.     

Errors in Results and Measurement Provisions

The relative and reduced errors of measurement provisions and the relative errors of measurements are considered. Analytical expressions are provided that make it possible to evaluate the errors in question. Conclusions and practical recommendations are given.Translated from Izmeritel’naya Tekhnika, No. 3, pp. 71–72, March, 2005.     

Dependence of the Spectroscopic Properties of Europium on the Spatial Distribution of Rare-Earth Ions in Fluorophosphate Glasses

Doped fluorophosphate glasses containing 4–13 mol % Ba(PO₃)₂ have been studied. Analysis of the Raman spectra has revealed that the structure of glasses containing up to 1 mol % Ba(PO₃)₂ involves isolated [PO₄] tetrahedra. An increase in the Ba(PO₃)₂ content brings about the formation of pyrophosphate groups, which are dominant in the glass containing 11 mol % Ba(PO₃)₂. The introduction of up to 2 mol % EuF₃ into the glasses containing 5 and 7 mol % Ba(PO₃)₂ leads to a decrease in the Landau-Placzek ratio. This is interpreted within the model of segregation of dopant ions. From analyzing the induced absorption spectra, the content of Eu³⁺ ions with a predominantly phosphate environment is estimated at ∼0.005 mol %. It is shown that, for the glasses containing 4 mol % Ba(PO₃)₂, the intensity ratio of the Eu³⁺ luminescence bands attributed to the ⁵ D ₀-⁷ F ₁ and ⁵ D ₀-⁷ F ₂ transitions changes with an increase in the EuF₃ content from 0.01 to 2.0 mol %. This dependence of the intensity ratio on the EuF₃ content exhibits a maximum at 0.5 mol % EuF₃, which is explained by the change in the local environment of the rare-earth ion.Original Russian Text Copyright © 2005 by Fizika i Khimiya Stekla, Bocharova, Karapetyan, Mironov, Tagil’tseva, Yanush.     

Infinite Point Group Quasicrystals: Symmetry Basis for Noncrystalline Diamond-like Materials

The construction of a diamond-like tetracoordinated quasicrystal (possible only in the infinite point group R) is considered in the framework of algebraic geometry. The physical and materials research applications of this approach are discussed.     

Genetic algorithms to reduce diagnostic information

A new genetic algorithm-based approach to the problem of reducing the diagnostic information acquired by testing discrete devices was proposed. Consideration was given to minimization and optimization of the diagnostic information for which the corresponding fitness functions and chromosome structures used in the genetic algorithms were suggested. Statistical data corroborating efficiency of the developed genetic algorithms for the problems under consideration were presented.