Investigation of the Mechanical Twinning of Antimony Single Crystals by Nanoindentation

The twinning of antimony single crystals in nanoindentation has been investigated. The role of twinning in the formation of the impression of the Berkovich pyramid on the surface (111) of antimony single crystals has been established. A new method of investigation of the mechanical twinning of single crystals has been developed. For the first time, the duration of the process of twinning has been determined experimentally by a direct technique.     

Made-to-order nanocarbons through deterministic plasma nanotechnology

Through a combinatorial approach involving experimental measurement and plasma modelling, it is shown that a high degree of control over diamond-like nanocarbon film sp3/sp2 ratio (and hence film properties) may be exercised, starting at the level of electrons (through modification of the plasma electron energy distribution function). Hydrogenated amorphous carbon nanoparticle films with high percentages of diamond-like bonds are grown using a middle-frequency (2 MHz) inductively coupled Ar+CH4 plasma. The sp3 fractions measured by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy in the thin films are explained qualitatively using sp3/sp2 ratios 1) derived from calculated sp3 and sp2 hybridized precursor species densities in a global plasma discharge model and 2) measured experimentally. It is shown that at high discharge power and lower CH4 concentrations, the sp3/sp2 fraction is higher. Our results suggest that a combination of predictive modeling and experimental studies is instrumental to achieve deterministically grown made-to-order diamond-like nanocarbons suitable for a variety of applications spanning from nano-magnetic resonance imaging to spin-flip quantum information devices. This deterministic approach can be extended to graphene, carbon nanotips, nanodiamond and other nanocarbon materials for a variety of applications.     

Electron-Conduction Mechanism and Specific Heat Above Transition Temperature in LaFeAsO and BaFe2As2 Superconductors

The ionization energy theory is used to calculate the evolution of the resistivity and specific heat curves with respect to different doping elements in the recently discovered superconducting pnictide materials. Electron-conduction mechanism in the pnictides above the structural transition temperature is explained unambiguously, which is also consistent with other strongly correlated materials, such as cuprates, manganites, titanates and magnetic semiconductors.     

Effect of nanovolumes of additives on the properties of motor oils. Theoretical principles

A method is proposed for scattered light correlation spectroscopy for objective evaluation of the effect of water, oxidation products, and particulate contaminants on the size of colloidal formations in petroleum oils with additives. It was shown that to increase the colloidal stability — resistance to separation of oils with additives — and correspondingly improve their performance properties, it is necessary to take into account the intermolecular interactions of the additives in composites and to ensure the minimum change in them under the effect of external factors. The mechanism of the reaction of the additives and their selection for ensuring the assigned performance properties of lube oils is theoretically substantiated. __________ Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 3, pp. 43–45, May–June, 2008.     

Correction to: Physical and Technological Aspects of Pulsed Laser Cutting of Cavities in Ceramics

Refractories and Industrial Ceramics - The following Acknowledgement is to be added to page 173 after the Conclusion: The work was financially supported by the Ministry of Education and Science of...     

The coalescence of twins in bismuth single crystals

The process of the coalescence of twin boundaries in bismuth single crystals has been studied. It has been established that the twin coalescence can occur without the formation of an interface between them or with the formation of a double twin boundary, depending on the direction of twin growth and orientation of twinning planes.