Single-crystal (001) rutile plate was irradiated intensively with 40 keV argon ions. Then, electromigration of oxygen vacancies was done in the irradiated rutile. The effect the concentration and charge state of oxygen vacancies has on the color, optical absorption spectra, and photoluminescence of rutile is shown.

Si single crystal was sequentially implanted with high doses (2∙1016 cm-2) of In+ and Sb+ ions with an energy of 30 keV in order to synthesize a layer of narrow-gap indium antimonide (InSb) in its near-surface region. Implanted Si:(In + Sb) layers in the liquid phase were annealed with a powerful pulsed ( 100 ns) ion beam (C+/H+) with an energy of 300 keV and a pulse-energy density of 1.0 J/cm2. Calculation of the total depth profile of the concentration of implanted In and Sb atoms taking into account ion sputtering showed their maximum concentration of 40 at.

The surface modification of a polished single-crystal c-Ge substrate irradiated with 115In+ ions at an energy of E = 30 keV, a current density of J = 5 μA/cm2, and a wide range of high doses D = 1.8 × 1015–7.2 × 1016 ion/cm2 is studied. The sample morphology is analyzed by high-resolution scanning electron microscopy. It is shown that when the value D = 1.9 × 1016 ion/cm2 is exceeded, the formation of a spongy porous structure (PGe) consisting of intertwining nanowires is observed. The geometric parameters of nanowires change with increasing D. Measurement of the optical reflection spectra R of the In:PGe layers demonstrated that the formed In:PGe material is characterized by a low value of the R coefficient in the spectral region of 220–1050 nm. Thus, such layer could serve as an effective antireflective coating.

The formation of amorphous thin surface layers of nanoporous Ge with various morphologies during the low-energy high-dose implantation by metal ions of different masses, namely 63Cu+, 108Ag+, and 209Bi+, on single-crystal c-Ge substrates was experimentally demonstrated using high-resolution scanning electron microscopy. The structure of the obtained nanoporous Ge layers was studied using backscattered electron diffraction. Under irradiation with low-energy ions, such as 63Cu+ and 108Ag+, needle-like nanostructures constituting a nanoporous thin Ge layer form on the surface of c-Ge. However when employing havier 209Bi+, the implanted layer consists of densely packed nanowires. At high ion-irradiation energies, the morphology of the thin surface layers of nanoporous Ge undergoes a sequential transformation in shape from three-dimensional reticulated to spongy as the mass of the implanted ions increased. Such a spongy structure was formed by sparse individual intertwining nanowires. The general potential mechanisms for pore formation in Ge during low-energy high-dose ion implantation are discussed, including the cluster–vacancy mechanism, local thermal microexplosion, and localized heating accompanied by surface melting with effective sputtering.

The electron paramagnetic resonance (EPR) spectra of oxygen-deficient rutile TiO2 – δ under photoexcitation at low temperatures in the range of 15–40 K were measured. Excluding the early described Ti3+ centers, concentration of which is independent of photoexcitation, new EPR signals appear at various wavelengths (λ) of photoexcitation taken in the range 400–460 nm. From the analysis of the EPR data we conclude that the observed EPR signals can be attributed to either the positive-charged oxygen vacancies ( V_O^ + ) with S = 1/2 (upon photoexcitation with λ ≤ 420 nm only), or more complex defects such as positively-charged [Ti3+–VO]+ pairs with S = 1/2 and neutral complexes of (Ti3+–VO–Ti3+) with S = 1. The latter is observed upon photoexcitation with a wavelength above 420 nm.

Single-crystal c-Ge plates implanted with Ag+ ions with an energy of E=30 keV, current density of the ion beam J = 5 μA/cm2 and a dose of D = 2.5· 1016 ion/cm2 were subjected to rapid thermal annealing by single light pulses of various durations from 1 up to 9.5 s. By scanning electron microscopy and optical reflection spectroscopy measurements it was shown that after ion implantation an amorphous porous Ag : PGe layer of spongy structure, consisting of Ge nanowires, is formed on the surface of c-Ge substrates. It was found that the annealing with an increase in the pulse duration up to 5 s successively leads to an increase in the Ge nanowire diameters from 26 to 35 nm. With longer pulses, the porous Ag : PGe structure is destroyed and Ag evaporates from the implanted layers. Keywords: nanoporous germanium, ion implantation, rapid thermal annealing.

The possibility of using a nanoporous Ge layer formed by implantation with 115In+ ions on a monocrystal c-Ge substrate as an antireflection optical coating (In:PGe) was studied. For this purpose, ion implantation of c-Ge wafers was performed at an energy E=30 keV, current density in the ion beam J=5 μA/cm2, and dose D=1.8· 1016 ion/cm2. It was shown that the fabricated In:PGe spongy layer, which consists of intertwining Ge nanowires, is characterized by a low reflectivity (~ 5%) in a wide optical spectral range of 250-1050 nm. Keywords: nanoporous germanium, ion implantation, antireflection optical coating.

The paper addresses the study of monocrystalline c-Ge wafers implanted by Ag+ ions at current density J=5 mu A/cm(2), dose D=2.5.10(16) ion/cm(2), energy 30 keV and subjected to rapid thermal processing annealing with single light pulses of various duration from 1 to 9.5 s. It was found that annealing with an increasing pulse duration to 5 s consequently leaded to growing diameters of Ge nanowires from 26 to 35 nm, which constitute an amorphous sponge-like structure of Ag:PGe with nanowires formed by ion implantation. It was assumed that increase in the nanowire diameters occurred by the mechanism of Ostwald ripening in the samples heated during the annealing. Annealing with the pulses exceeding 5 s caused the porous structure destruction and Ag evaporation in the samples. Partial recrystallization of the implanted Ag:PGe layers annealed by incoherent light pulses with duration of more than 1 s was observed.

The possibility of using a nanoporous Ge layer formed by implantation with 115 In+ ions on a monocrystal c-Ge substrate as an antireflection optical coating (In:PGe) was studied. For this purpose, ion implantation of c-Ge wafers was performed at an energy E = 30 keV, current density in the ion beam J = 5 μA/cm2, and dose D = 1.8 × 1016 ion/cm2. It was shown that the obtained In:PGe spongy layer, which consists of intertwining Ge nanowires, is characterized by a low reflectivity (~5%) in a wide optical spectral range of 250–1050 nm.

The high-dose implantation of Co+ ions into the rutile (TiO2) structure induces the formation of ferromagnetism and two magnetic phases in it: metallic cobalt nanoparticles and a divalent cobalt ion solid solution. The effect the temperature and orientation of the TiO2 substrate have on the ferromagnetism and magnetic phase composition of rutile upon ion exposure and subsequent annealing in air or a vacuum is demonstrated.

A monocrystalline rutile (TiO2) plate implanted with cobalt ions at a fluence of 1.25∙1017 ions/cm3 with energy 40 keV at constant current density in the ion beam of 2 μA/cm2 when the temperature of the irradiated substrate was maintained at 620°C was studied using light reflection and transmission spectroscopy in the visible spectral region. The spectral dependences of the optical parameters of the modified layer were obtained. The calculated optical Tauc gap of the layer was 0.2–0.3 eV.

Objects of the study were colorless single crystals of quartz with a total amount of impurities lesser than 1%. Implantation of vanadium ions into the quartz structure was carried out parallel to the symmetry axis C. Irradiation doses varied from 0.75 × 1017 to 1.5 × 1017 ion/cm2. With the purpose to anneal radiation defects and to redistribute the implanted vanadium admixture, the post-implanting heat treatment was carried out in the air atmosphere, within the range 200–1000 °C. There was solved issue of ion-beam modification of the colorimetric properties of the quartz matrix with simultaneous control of change in the nature of color of the piezo quartz raw material. In result of the study, samples with annealing temperatures of 383 and 585 °C were investigated most thoroughly by methods of adsorption optical spectroscopy. The quartz sample with annealing temperature 383 °C has acquired an olive-green color due to formation of oxide nanoprecipitates of vanadium ions with different valences: V2+, V3+, V4+. The quartz sample with annealing temperature 585 °C become discolored in result of oxidation of vanadium ions and their transition in the pentavalent state V5+.

The point defects have been produced in the rutile structure by irradiation of a single crystalline (001)-TiO2 rutile platet wih 40 keV Ar+ ions. It is found that Ar-ion bombardment of rutile results in a large number of positively charged oxygen vacancies and, as a consequence, leads to a change in the valence of neighbouring Ti cations. Electron paramagnetic resonance (EPR) of Ar-ion irradiated TiO2 rutile is studied in detail. The analysis of angular , temperature dependences of EPR spectra makes it possible to conclude that EPR signals are associated with Ti3+ ions in the sixfold symmetric environment. In addition to the main signal from even titanium isotopes, eight equidistant weak lines are observed due to the hyperfine interaction typical for two titanium isotopes: 47Ti with a nuclear spin I = 5/2 (natural abundance of 7.4%) and 49Ti with a nuclear spin I = 7/2 (natural abundance of 5.4%). By comparing the g-tensor components with the reference data it is concluded that these Ti3+-based centers in Ar-ion implanted rutile were not described before.

A new approach for fabrication of grid structures on substrates (devices) for visual characterization of ultra-small biological objects is presented. By Ar+-ion mask implantation of silica substrates is applied to create grid structures with cells of 25 mu m size and a depth of 100 nm. Demonstration of efficiency of such structures was carried out by scanning electron microscopy observation and energy dispersive spectrometry - EDX analysis using substrates with deposited Staphylococcus bacteria.

Thin films with the uniaxial magnetic anisotropy were synthesized by Fe+ implantation into single-crystal silicon in the external magnetic field. The induction of the magnetic anisotropy is due to the directional atomic pair ordering (Néel-Taniguchi model). The applicability of this model is confirmed by experiments on the rotation of the direction of the easy magnetization axis by repeated low-dose implantation in an external magnetic field. The induced anisotropy is formed in the collisions cascade region characterized by the so-called «dynamic temperature». The value of the dipole interaction coefficient, calculated taking into account the dynamic temperature, agrees with the results obtained in other works. The value of anisotropy constant is inversely proportional to temperature. Possible mechanism leading to such dependency is discussed.

In this work, we investigated the possibility of using a nanoporous Ge layer (p-Ge) formed by implantation with Ag+ ions on a single crystal c-Ge substrate as an anode electrode for a lithium-ion battery. For this, ion implantation of c-Ge plates was carried out at an energy of E = 30 keV, a current density in the ion beam of J=5 μA/cm2, and a dose of D=1.3·1016 ion/cm2. It is shown that the obtained spongy Ag:p-Ge layers, consisting of intertwining Ge nanowires, demonstrate a high Coulomb efficiency (> 97%) after the first cycle and show up to 79.5% of reversible capacity after 1000 cycles.

In this work, the possibility of using a nanoporous Ge layer (p-Ge), formed by implantation with Ag+ ions on a single crystal c-Ge substrate, as an anode electrode for a lithium-ion battery was studied. For this, the ion implantation of c-Ge substrutes was carried out at an energy of E=30 keV, a current density of J=5 μA/cm2, and a dose of D=1.3·1016 ion/cm2. It was shown that the obtained spongy Ag:p-Ge layers, consisting of intertwining Ge nanowires, demonstrate a high Coulomb efficiency (>97%) after the first cycle and show up to 79.5% of reversible capacity after 1000 cycles. Keywords: nanoporous germanium, ion implantation, anod, lithium-ion battery.

Single-crystal c-Ge plates implanted with Ag+ ions with an energy of E=30 keV, current density of the ion beam J = 5 μA/cm2 and a dose of D=2.5×1016 ion/cm2 were subjected to rapid thermal annealing by single light pulses of various durations from 1 up to 9.5 s. By scanning electron microscopy and optical reflection spectroscopy measurements it was shown that after ion implantation an amorphous porous Ag:PGe layer of spongy structure, consisting of Ge nanowires, is formed on the surface of c-Ge substrates. It was found that the annealing with an increase in the pulse duration up to 5 s successively leads to an increase in the Ge nanowire diameters from 26 to 35 nm. With longer pulses, the porous Ag:PGe structure is destroyed and Ag evaporates from the implanted layers.

The study addresses the monocrystalline c-Ge substrates implanted by Ag+ ions with the energy of 30 keV, irradiation dose of 7.5.10(16) ion/cm(2) at current density of 8 mu A/cm(2) and annealed by incoherent-light pulse. By scanning electron microscopy and optical reflection spectroscopy measurements it was shown that after ion implantation an amorphous porous Ag:PGe layer of a spongy structure with nanowires on the c-Ge substrate were formed. Pulsed light annealing of the implanted samples leads to partial melting and recrystallization of the surface Ag:PGe layer. The spongy annealed structure of the Ag:PGe layer was not destroyed, however the diameters of nanowires increased by about 1,5 times.