Konstantin Iakoubovskii

Thickness measurements with electron energy loss spectroscopy

Measurements of thickness using electron energy loss spectroscopy (EELS) are revised. Absolute thickness values can be quickly and accurately determined with the Kramers‐Kronig sum method. The EELS data analysis is even much easier with the log‐ratio method, however, absolute calibration of this method requires knowledge of the mean free path of inelastic electron scattering λ. The latter has been measured here in a wide range of solids and a scaling law λ ∼ ρ−0.3 versus mass density ρ has been revealed. EELS measurements critically depend on the excitation and collection angles. This dependence has been studied experimentally and theoretically and an efficient model has been formulated. Microsc. Res. Tech., 2008.

High-resolution electron microscopy of detonation nanodiamond

The structure of individual nanodiamond grains produced by the detonation of carbon-based explosives has been studied with a high-vacuum aberration-corrected electron microscope. Many grains show a well-resolved cubic diamond lattice with negligible contamination, thereby demonstrating that the non-diamond shell, universally observed on nanodiamond particles, could be intrinsic to the preparation process rather than to the nanosized diamond itself. The strength of the adhesion between the nanodiamond grains, and the possibility of their patterning with sub-nanometer precision, are also demonstrated.

Impact bonding and rebounding between kinetically sprayed titanium particle and steel substrate revealed by high-resolution electron microscopy

Micrometres-sized titanium particles were deposited on a steel substrate by kinetic spraying at an impact velocity of about 760u2009mu2009s−1, and the bonding between titanium and steel was characterized by high-resolution electron microscopy. A thin interfacial layer composed of titanium, oxygen and iron was identified between the particle and the substrate. Moreover, although titanium particles appeared well bonded to the substrate, their central parts did partially detach. Remarkably, the detachment occurred not at the titanium/steel interface but inside the steel substrate.

Techniques of aligning carbon nanotubes

This paper reviews major techniques of aligning carbon nanotubes, either during the growth or by the post-growth processing. A number of post-processing alignment techniques are discussed, which employ mechanical stretching, fracture, compression, friction, filtration, fiber drawing, gas flow, liquid crystals, Langmuir-Blodgett technique, acoustic, magnetic and electric fields. The suitability of those techniques to industrial applications is analyzed.

Elastic scattering of 200 keV electrons in elemental solids: experimental observation of atomic-number-dependent oscillatory behavior

Mean free path of elastic electron scattering λ(el) has been measured with a 200xa0keV transmission electron microscope for a wide range of stable elemental solids. An oscillating behavior versus atomic number Z has been revealed, such that, within one row of the periodic table, λ(el) exhibits minimum (maximum) for elements with completed (empty) outer d shells. These λ(el)(Z) oscillations are attributed to Z dependence of the atomic density, and their importance for the interpretation of electron microscope images is demonstrated.

Focus on Advanced Nanomaterials

The Nobel Prize in Physics 2010 was awarded to Andre Geim and Konstantin Novoselov for groundbreaking experiments regarding the two-dimensional material graphene. This award acknowledged the growing importance of graphene, as well as of nanomaterials and surface phenomena at the nanoscale in general. Graphene, carbon nanotubes and many other nanostructures have already demonstrated their remarkable physical properties and a wealth of quantum phenomena. However, much work has to be done to apply these properties in practical devices and technological processes. This focus issue overviews some recent advances in this direction. It includes a foreword and eight articles on nanomaterials investigation carried out at International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science. The foreword is written by Heinrich Rohrer, who received the Nobel Prize in Physics in 1986 for the design of the scanning tunneling microscope (STM)?one of the most successful tools in the characterization and manipulation of various nanomaterials, including graphene. Professor Rohrer presents his perspectives on the trends in the past, present and future developments of nanoscience and nanotechnology. Graphene and carbon nanomaterials dominate the topics of this focus issue. Rao et al review the synthesis and characterization of the surface, magnetic and electrical properties of carbon structures containing one to several graphene layers. Moriyama et al present their recent results on the fabrication of electrical quantum-dot devices in a graphene-based two-dimensional system. By applying a nanofabrication process to graphene flakes, they fabricated a device comprising two lateral quantum dots coupled in series. Wakabayashi et al review the theoretical treatment of graphene nanoribbons and present their own recent achievements in this area. Graphene is closely related to carbon nanotubes, and their applications largely rely on the possibility of controllable functionalization. Gautam et al review an elegant method of such functionalization, namely the encapsulation of inorganic elements and compounds into carbon nanotubes. Functionalization of metal surfaces is another important topic of this focus issue. Nagao et al overview the fundamental properties of plasmons in materials with various dimensionalities. In particular, they consider antenna resonances of plasmon polariton in some widely used nanometer-scale structures and atomic-scale wires, along with their applications. Komeda et al present their molecule-resolved STM analysis of bonding metal-free phthalocyanine to gold surfaces. Such organic?inorganic interfaces have a variety of potential applications to catalysis and sensors. Nagasaki describes another organic nanotechnology related topic, namely engineering of poly(ethylene glycol) tethered chain surfaces for high-performance bionanoparticles. Finally, Fabbri et al review the role of interfaces in ionic conductivity in oxide hetero-structures, aimed at improving the design of micro-ionic devices. We hope that this focus issue will provide a valuable update on some topics in current nanomaterials research.

Interfaces of Xe Inclusions Ion-implanted in Al - Ordering in a Fluid Xe and Matrix Oxidation at Surfaces

Inert gases sometimes behave in strange manner. Xe, for instance, becomes solid nano-crystals when it is ion-implanted into Al [1]. It is known that the precipitates with the size less than 5 nm in Al have an FCC structure, aligned with the matrix. The lattice parameter of this solid Xe is 50 percent larger than that of Al [2]. However, these crystals sometimes melt to fluid under electron irradiation under the observation in the electron microscopes. We used high-resolution transmission electron microscopy (HRTEM) and high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) to image and model an atomic structure of Xe inclusions [3, 4] and to investigate the interface structures when it is solid or fluid.