Six-fold in-plane magnetic anisotropy in Co-implanted ZnO (0001)

Magnetic anisotropies of Co-implanted ZnO (0001) films grown on single-crystalline Al2O3 (11-20) substrates have been studied by ferromagnetic resonance (FMR) technique for different cobalt implantation doses. The FMR data show that the easy and hard axes have a periodicity of 60 degrees in the film plane, in agreement with the hexagonal structure of the ZnO films. This six-fold in-plane magnetic anisotropy, which is observed for the first time in ZnO-based diluted magnetic semiconductors, is attributed to the substitution of cobalt on Zn sites in the ZnO structure, and a clear indication for long range ferromagnetic ordering between substitutional cobalt ions in the single-crystalline ZnO films.Comment: 7 pages, 4 figure

Optical properties and crystal chemistry of synthetic rutile implanted with cobalt ions

Implantation of high-energy cobalt ions into plates of synthetic rutile has been studied, and absorption, luminescence, and luminescence excitation spectra have been recorded and interpreted. Long-wave luminescence (820 nm) of TiIV 3+ ions in rutile has been revealed; its intensity increased after the cobalt implantation. Analysis of luminescence and luminescence excitation spectra has allowed us to specify the scheme of electron energy levels of rutile and to establish the energy levels of impurity Ti3+ ions occupying vacant octahedrons with the C2h symmetry in structure of the mineral. © Pleiades Publishing, Ltd. 2007

Formation of anisotropic ferromagnetic response in rutile (TiO2) implanted with cobalt ions

The (1 0 0)- and (0 0 1)-monocrystalline plates of rutile (TiO2) were implanted by 40 keV Co+ ions with fluences in wide range of 0.15-1.5 × 1017 ion/cm2 to study the development of ferromagnetism in the diamagnetic TiO2. With increase of fluence the implanted rutile plates reveal sequentially paramagnetic, superparamagnetic, weak ferromagnetic and, eventually, strong anisotropic ferromagnetic response at room temperature. The thermo-magnetic analysis shows that the ferromagnetic samples exhibit two magnetic transitions with temperatures of the ferromagnetic ordering TC1 ∼ 700 K and TC2 ∼ 850 K, correspondingly. Heating of the samples in air strongly suppresses the ferromagnetic phases if the temperature of heating exceeds the corresponding transition temperature. Subsequent high-vacuum annealing restores only the low-temperature ferromagnetic phase. The origin of the two magnetic phases and anisotropy of the ferromagnetism in the Co-implanted rutile are discussed in the model of two cobalt-rich layers with different concentration and valence states of the implanted cobalt. © 2007 Elsevier B.V. All rights reserved

Instruments of investment attraction in order to fulfill the structural priorities of sustainable regional development (study based on the Rostov Region)

The aim of the study is devoted to defining most effective tools of investment funds attraction. These funds can be used in implementation of strategic priorities for socio-economic regional development requiring, in areas that are in need of economic restructuring. The authors have selected the Rostov region as the research target, the economy of which is in need of structural change in the direction of increasing innovational, high-tech and scientific production, in order to reduce import dependency and move closer towards the post-industrial model of economic development. The study considers currently available instruments of attraction of private sector closer to solving the stated problems of Rostov region, analyzing their regulatory, financial and organizational consulting security on both state and federal level. Main directions of economic restructuring of Rostov region are also defined. Authors also outline the main problems that private enterprises come across while doing business in the investigated area. On the basis of the research, investigating federal and regional instruments of private sector involvement authors form a number of proposals and recommendations focusing on regional improvement. As a result of the conducted study, the authors reached the conclusion, that there is a number of strategic measures that should be performed in the Rostov region. These don't only include the improvement of financial instruments, but also best available technologies, national technology initiative, and clustering.peer-reviewe

Coloration of natural beryl by iron ion implantation

Natural colorless crystals of Ural beryl were implanted at room temperature with 40 keV Fe+ ions with fluences in the range of 0.5-1.5×1017 ion/cm2. As-implanted samples show dark-grey tone due to radiation damage of beryl crystal. Subsequent thermal annealing of irradiated crystals in oxygen at 600 °C for 30 min results in the color change, to yellowish or yellow-orange tones with golden luster, depending on value of iron fluence. The nature of beryl coloration was studied by optical absorption, Mössbauer and Rutherford backscattering (RBS) spectroscopes. It was established that the thermal treatment of iron-irradiated beryl lead to inward diffusive redistribution of iron ions. An appearance of optical absorption bands connected with charge-transfers O2-→FeVI 3+ and O2-→FeIV 2+, FeIV 3+ determine the yellow tone in colored beryls. Most of implanted iron ions are founded in both tetrahedral FeIV 2+ and octahedral FeVI 3+ sites where they may substitute beryllium and aluminum host ions by isomorphic way. © 2003 Elsevier Science B.V. All rights reserved

Ion metal synthesis in viscous organic matter

The viscosity of the irradiated target as new parameter was introduced in ion implantation physics of organic matter. It was experimentally shown that using this parameter one enables to monitor the process of ion synthesis of thin granular impurity films. As an example, the results of high-dose implantation of Co+ and Ag+ ions in viscous epoxy experimenting stages of cure (polymerization) process are presented. It was established by TEM that the mean size, size distributions, form and crystalline structure of the synthesized metal particles depend on both ion beam parameters and viscosity of the epoxy target. The mechanisms of homogeneous nucleation and diffusive growth of metal particles in the low-viscosity epoxy in contrast to heterogeneous nucleation in solid polymers are discussed. The threshold implantation dose that is necessary for the formation of stable metal phase nucleation in a viscous medium was calculated by using the diffusion equation with a continuous Gauss-like source for the implanting impurity. It is shown that the specificity of epoxy polymerization influences the growth and crystalline structure of metal particles at intermediate stages of the epoxy cure process. The preliminary investigation of magnetic, optical and electrical properties of synthesized films is described as well

Microstructure and magnetic properties of strontium titanate implanted with iron

© 2017, Allerton Press, Inc. The magnetic phase composition of strontium titanate surface layers implanted with iron ions is studied by means of Mössbauer spectroscopy, and by measuring alternating current magnetic susceptibility. It is shown that the interaction between α-Fe nanoclusters at high concentrations of the implanted admixture produces ferromagnetic order in samples at room temperature

Differential expression of HERV-W in peripheral blood in multiple sclerosis and healthy patients in two different ethnic groups

Copyright © 2020 Tarlinton, Wang, Morandi, Gran, Khaiboullin, Martynova, Rizvanov and Khaiboullina. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. Overexpression of the Human endogenous retrovirus W (HERV-W) group of inherited retroviruses has been consistently linked with Multiple Sclerosis (MS). However most of the studies on this link have focused on European genetic groups with a very high risk of MS and it is not clear that this relationship holds for all ethnic groups. This study examined via qPCR the RNA expression in peripheral blood of HERV-W (the multiple sclerosis associated retrovirus variant MSRV) of MS patients and healthy controls from two ethnic groups with very different risk rates of MS. Population one was derived from the UK with a Northern European genetic background and an MS risk rate of 108/100,000, population two was derived from the republic of Tatarstan, Russian Federation, with a mixed Russian (Eastern European) and Tartar (Turkic or Volga/Urals) population with an MS risk rate of 21-31/100,000. The Russian population displayed a significantly higher basal level of expression of MSRV in both healthy and MS individuals when compared to the British control population with a trend in the Russian population towards higher expression levels in MS patients than healthy patients