Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques

Expressions are obtained for dynamic stresses appearing when high-energy particles pass through a crystal. The nonuniform distribution of stresses over the crystal can lead to the rearrangement of atoms knocked out by a particle, as well as to the formation of clusters.

The results of investigations of the flashover of ZrO2, HfO2, and CeO2 coatings with a thickness of up to 100 μm, which are sputtered onto metallic substrates, are represented. The composition and structure of the coatings are investigated. It is shown that the highest flashover voltage is demonstrated by the CeO2 coating with the “cauliflower” structure.

The results of studying thin films and superlattices of rare-earth helimagnets Dy and Ho using a neutron reflectometer are presented. Neutron reflectometry is shown to allow the magnetic phase transitions in these nanostructures to be studied and information about the periodicity of magnetic helices in them to be collected. It is proposed to create a neutron reflectometer capable of conducting polarization analysis on the DARIA compact neutron source, optimized for studying long-period magnetic ordering in rare-earth helimagnets, and the possible directions of this optimization are indicated.

We present the results of the study of the elemental composition and defects of the electronic structure of the surface layer modified by high-dose irradiation (1018–1019 ion/cm2) of highly oriented pyrolytic graphite (UPV-1T) by 30-keV N 2 + and Ar+ ions in the temperature range from 180 to 400°C. The EPR spectra observed during irradiation with argon ions at high temperatures and with nitrogen ions at temperatures near the liquid-nitrogen temperature T = 77 K exhibit anomalously narrow lines which probably result from the exchange interaction inside paramagnetic clusters of displaced carbon atoms. During nitrogen ion irradiation at room and higher temperatures, paramagnetic defects typical of many carbon materials (single EPR lines with g = 2.0027–2.0029) and belonging to carbon atoms bound to one or three nitrogen atoms were detected.

The formation of nanocrystals under deformation in Al-, Fe-, and Co-based amorphous alloys are studied using X-ray diffraction and transmission and scanning microscopy methods. It is shown that the presence of shear bands in deformed amorphous alloys is an insufficient condition for nanocrystal formation. The presence of a large number of intersecting shear bands and an increase in the material temperature in the shear-band region in the case of intense plastic deformation contributes to nanocrystal formation.

Hydrophilicity of the aluminium thin film’s surface is one of the imperative surface characteristics needed for metal pad bonding process in microelectronic circuitries. In this paper, we present a study on the influence of argon plasma exposure on the surface properties of sputter-deposited aluminium thin film layer. The exposure of aluminium thin film layer in argon plasma at atmospheric pressure and low pressure are carried out and compared. The water contact angle and surface topology of the aluminium’s surface are inspected. The aluminium–gold metal–metal ohmic contact resistance and the aluminium thin film sheet resistivity are measured. Argon plasma has modified the originally hydrophobic aluminium’s surface into hydrophilic profile, which may be related to its increase of surface energy. Higher/smaller thin film surface roughness has been measured from the low-pressure/atmospheric-pressure argon plasma exposure that produces thin film with higher (9.64 Ω)/smaller (6.78 Ω) contact resistivity compared to the unexposed aluminium thin film layer (7.85 Ω). The argon plasma exposure treatment on the aluminium thin film has generally improved its surface properties, inducing hydrophilicity surface profile for the aluminium metal pad. The conducted treatment at the atmospheric pressure level specifically helps to reduce the surface roughness and increase the thin film layer conductivity.

It has been established that nickel condensates in the form of low-dimensional porous systems can be obtained at quasi-equilibrium steady-state condensation. On the basis of the structural-morphological characteristics obtained at different condensate growth stages, it has been shown that porosity formation occurs without coalescence upon reorientation of the condensed flux in the region of the initial cluster aggregation and also when homonucleation of new clusters takes place in the regions of the initial cluster intergrowth.