The work examines the doping of a Si1 – xGex solid solution with donor (Sb, P) and acceptor (B) impurities during the synthesis process using electric pulse plasma sintering from powders with submicron particle sizes. The impurity content varied from 0.5 to 2.0 at

The conditions for the growth of n-type Ge layers with the parameters required to create a Ge-MISFET with an induced p-type channel using the hot wire chemical vapor deposition (HW CVD) method are determined. The conditions for deposition using electron beam deposition and subsequent annealing of the subgate high-k dielectric ZrO2:Y2O3 layers are optimized, allowing us to achieve a leakage current value of 5 × 10–6 A/cm2. For the developed device structure, some parameters of the Ge-MISFET are calculated, such as the channel length, maximum voltage between the sink and source, and breakdown voltage.

The paper presents the results of the study of the kinetics of the growth of epitaxial Ge layers on Ge substrates of various orientations. The features of pregrowth preparation of substrates and methods of low-temperature growth of homoepitaxial layers by gas-phase deposition reinforced with «hot wire» are given. Structural and electrical properties of epitaxial structures are investigated

It has been established that the physicochemical properties of structures based on iron silicides formed by ion implantation of iron ions into silicon depend significantly on the time of subsequent high-temperature annealing. Objects with different geometric parameters are formed on the surface and the roughness increases. Annealing at 1000 C in an Ar atmosphere is accompanied by a decrease in the content of the Fe-Si chemical bonds during the first 60 seconds. The reason for the drop in thermal conductivity with increasing annealing temperature is the formation of silicide complexes.

The magnetic properties and micromagnetic structure of [Co/Pt]10 multilayer magnetic films formed by independent variation of the Co and Pt layer thicknesses have been studied. The possibility of the film magnetization parameters manipulation was shown. It is found that the micromagnetic structure of the layers is significantly modified with a change in the thickness of the layers which correlates with the magnetization data. In particular, magnetic force microscopy revealed a system of magnetic skyrmions for a number of structures. The skyrmion density was found to be dependent on the growth conditions which in turn correlates with the shape of the magnetic hysteresis loop. Changing the thickness of the Co and Pt layers makes it possible to control the density of skyrmions in the range from 0.2 to 10.5 µm-2.

This paper presents the results of developing a technique for low-temperature growth of high-quality Ge and GeSn layers grown on Si(100) substrates, as well as the results of studies of their structural and electrical properties.

Methods of magnetic force microscopy are developed that make it possible to visualize the evolution of the domain structure that occurs when scanning a sample with a magnetic probe. The new technique is used to study the formation in CoPt thin films the skyrmions, a characteristic feature of which is Dzyaloshinskii–Moriya interaction. Changes in the position, shape, and size of the skyrmions when exposed to the probe’s magnetic field are described experimentally.

Operation modes of laser structures with controlled polarization of light have been studied and the results of measuring polarization characteristics are presented. The possibility of controlling both the linear and circular polarizations of light with corresponding modification of the laser design is shown. In particular, stable lasing at two orthogonally polarized modes in the near-IR range with the intensity ratio of radiation components ITE/ITM ≈ 4.5 is implemented. The possibility is confirmed of generation of circularly polarized radiation in edge-emitting laser diodes by magnetization of a combined semitransparent mirror with a ferromagnetic CoPt layer deposited on the end face of the laser cavity. The degree of polarization is ±1.25% in the CoPt layer saturation magnetization mode.

In this paper, we propose a method for predicting the refractive index variation in InGaAlAs tunnel-coupled quantum wells under the action of an electric field. Complex of mathematical and experimental studies to optimize the heterosystems design forthe semiconductor modulator construction according to a planar Mach-Zehnder interferometer scheme is demonstrated.

Heteroepitaxial Ge or Ge 1-x Sn x layers were grown by hot-wire chemical vapor deposition on Si(001) substrates doped heavily with a donor (As or Sb) impurity. The same layers were also grown on high-resistance Si(001) substrates for comparison. The depth profiles of carrier concentration were measured in both types of layers using the capacitance-voltage method, and carrier mobilities were measured additionally by the Hall effect method in layers on high-resistance silicon. It was found that the layers grown on high-resistance substrates were p-type, while the layers grown in the same regimes on heavily doped substrates were n-type with electron concentration n=(4-9)·10 16 cm -3 in Ge layers and n=(2-4)·10 17 cm -3 in GeSn layers. It was established experimentally and theoretically that the effect of autodoping of Ge and GeSn layers is lacking in the hot-wire chemical vapor deposition method. In our view, the growth of n-type Ge and GeSn layers on n + -Si(001) substrates doped heavily with a donor (As or Sb) impurity is associated with the segregation of this impurity in the process of growth of a buffer Si layer and its subsequent incorporation into growing Ge or GeSn layers. Keywords: epitaxy, doping, Ge, Si, Sn, concentration.

Методом химического осаждения из газовой фазы, активированной "горячей нитью", выращены гетероэпитаксиальные слои Ge или Ge1-xSnx на высоколегированных донорной примесью (As или Sb) подложках Si(001). Для сравнения такие же слои были выращены на высокоомных подложках Si(001). В тех и других слоях вольт-емкостным методом были измерены профили распределения концентрации носителей заряда по глубине слоев, а в последних слоях дополнительно методом эффекта Холла были измерены подвижности носителей заряда. Установлено, что слои, выращенные на высокоомных подложках, были p-типа проводимости, а слои, выращенные в тех же режимах на высоколегированных подложках, были n-типа с концентрацией электронов в слоях Ge n=(4-9)·1016 см-3, а в слоях GeSn n=(2-4)·1017 cм-3. Экспериментально и теоретически установлено, что эффект автолегирования слоев Ge и GeSn в методе химического осаждения из газовой фазы, активированной "горячей нитью", отсутствует. По нашему мнению, формирование слоев Ge и GeSn n-типа проводимости при выращивании их на высоколегированных донорной примесью (As или Sb) подложках n+-Si(001) связано с сегрегацией этой примеси при росте буфферного слоя Si и с последующим встраиванием ее в растущие слои Ge или GeSn. Ключевые слова: эпитаксия, легирование, Ge, Si, Sn, концентрация.

The possibilities of controlled exposure to ion irradiation (He+ with an energy of 20 keV and a fluence in the range from 3·1014 to 3·1015 cm-2) as a method for modifying the magnetic properties and domain structure of Co0.35Pt0.65 thin ferromagnetic films have been studied. It was found that the ion irradiation causes a change in the Dzyaloshinskii--Moriya interaction constant and a change in the skyrmion density that correlates with it. This result shows the possibility of homogeneous ion irradiation as a way to control the micromagnetic structure, namely the process of formation of skyrmion states. Keywords: ferromagnetic thin films, ion irradiation, domain structure, magnetic force microscopy, Dzyaloshinskii-Moriya interaction, skyrmions.

A comparative study of the circular polarization degree dependences on external magnetic field was carried out in spin light-emitting diodes including semiconductor InGaAs/GaAs heterostructure and a magnetic CoPt contact and in control non-magnetic structures with an Au contact. In a weak magnetic field, the magnetic field dependence of electroluminescence circular polarization degree is similar to the magnetic field dependence of magnetization: it represents a hysteresis loop with saturation in a field of ~ 0.3 T. In a strong magnetic field, an additional linear contribution to the circular polarization degree is detected. This contribution is associated with the Zeeman splitting of energy levels. The magnitude of the linear contribution depends on the position of the quantum well relative to the ferromagnet/semiconductor interface. The obtained dependence is associated with the influence of the magnetic field of the inhomogeneously magnetized CoPt electrode on the spin relaxation time of carriers.

The possibilities of controlled exposure to ion irradiation (He+ with an energy of 20 keV and a fluence in the range from 3×1014 to 3×1015 cm–2) as a method for modifying the magnetic properties and domain structure of Co0.35Pt0.65 thin ferromagnetic films have been studied. It was found that the ion irradiation causes a change in the Dzyaloshinsky-Moriya interaction constant and a change in the skyrmion density that correlates with it. This result shows the possibility of homogeneous ion irradiation as a way to control the micromagnetic structure, namely the process of formation of skyrmion states.

In this work, we demonstrate the possibility of using a diluted magnetic semiconductor GaAs:Fe as a ferromagnetic injector in a spin light-emitting diode based on a GaAs/InGaAs quantum well heterostructure. It is shown that in such a device it is possible to observe partially circularly polarized electroluminescence at room temperature.

Приведены результаты исследования режимов работы лазерных структур с управляемой поляризацией света, в том числе результаты измерения поляризационных характеристик. Показана возможность управления как линейной, так и циркулярной поляризацией света при соответствующей модификации конструкции лазера. В частности, осуществлена устойчивая лазерная генерация на двух ортогонально-поляризованных модах в ближнем ИК диапазоне с соотношением интенсивностей компонент излучения ITE/ITM~ 4.5. Реализована возможность генерации циркулярно-поляризованного излучения в торцевых лазерных диодах посредством намагничивания комбинированного полупрозрачного зеркала с ферромагнитным слоем CoPt, нанесенного на торец лазерного резонатора. В режиме насыщения намагниченности слоя CoPt значение степени поляризации составило ±1.25%. Ключевые слова: полупроводники, лазерный диод, квантовая яма, поляризация.

Conducting ferromagnetic nanosized filaments consisting of Ni atoms are formed in thin ZrO2(Y)/Ni films using an atomic force microscope probe. The contact of the probe to such films (a virtual composite memristor device) exhibits resistive switching of the bipolar type associated with the destruction and restoration of Ni filaments in the ZrO2(Y) film. The region in which the conductive filament emerges onto the surface of the ZrO2(Y) film manifests itself in the magnetic force image as a single-domain ferromagnetic particle.

The possibility of using He+ ion implantation with an energy of 20 keV for modifying the domain structure and magnetic properties of CoPt films formed by electron beam evaporation with different compositions - Co0.45Pt0.55 and Co0.35Pt0.65 - has been investigated. For the irradiated CoPt samples of both compositions, a decrease in the coercivity (narrowing of the hysteresis loop on the magnetic field dependences of the Faraday angle and magnetization) with an increase in the He+ ion fluence from 2×1014 to 4×1014 cm−2 was found. In this case, the remanent magnetization of the Co0.35Pt0.65 films coincides with the value of saturation magnetization, while for Co0.45Pt0.55, a decrease in the remanent magnetization is observed. Magnetic force microscopy has shown that for the Co0.45Pt0.55 alloy, with an increase in the ion fluence up to 3 × 1014 cm−2, the largest number of isolated circular domains (skyrmions) is formed, while for He+ irradiation with a fluence of 4×1014 cm−2 for Co0.35Pt0.65, in addition to isolated circular domains, 360-degree domain walls (1D skyrmions) are observed. At the same time, the study of CoPt films by the Mandelstam-Brillouin spectroscopy method revealed an increase in the shift between the Stokes and anti-Stokes components of the spectrum and thus a significant increase of the Dzyaloshinsky-Moriya interaction for the irradiated samples. Simulation using the SRIM software showed that the applied ion irradiation causes the asymmetric mixing of Co and Pt atoms and thus, this may underlie the mechanism of the of the ion irradiation on magnetic properties and domain structure in CoPt films.

Diode structures with ferromagnetic narrow-gap semiconductors A3FeB5 as only p-region (p-GaFeSb/n-InGaAs), only n-region (n-InFeSb/p-InGaAs), p- and n-regions (p-GaFeSb/n-InFeSb, p-GaFeSb/n-InFeAs) for p-n junction were fabricated by pulsed laser deposition in vacuum. The composition of ferromagnetic semiconductor layers and their thicknesses, determined by X-ray photoelectron spectroscopy, generally correspond to the technological data for diode structures. In particular, the thickness of the GaFeSb layer is 25–30 nm, and the thickness of the InFeAs and InFeSb layers is 35–40 nm. The iron content in InFeSb ranges from 25 to 35 at.%. The GaFeSb layer contains from 15 to 41 iron at. %, and the InFeAs layer - 35 iron at. %. The chemical analysis of the structures revealed the presence of chemical bonds Fe-As (Sb), In-Fe and Fe-Ga. Therefore, it can be assumed that Fe atoms in the fabricated structures can substitute for elements of groups III and V simultaneously. All structures exhibit the effect of negative magnetoresistance at sufficiently low observation voltages of the effect (up to 50 mV), in low magnetic fields (up to 3600 Oe), and at high measurement temperatures. For GaFeSb/InFeSb, GaFeSb/InFeAs diodes, negative magnetoresistance was first observed at room temperature. The hysteresis form of the dependences of the resistance on the magnetic field suggests the effect of the ferromagnetic properties of the layers of narrow-gap semiconductors on the transport of carriers in the structures.