Arrays of vertically oriented carbon nanotubes (VOCNTs) with a height from 25 to 100 μ m and a specific resistance from 1.5 to 4 Ω cm have been grown by catalytic chemical vapor deposition on the Si/HfO _2 /Fe surface for the first time. The growth of VOCNTs on hafnium oxide is observed within a temperature range of 625-725 °C and does not occur at T≥ 750 °C. At the same time, the temperature dependence of the VOCNT growth rate is characterized by a value of ∼ 1.5 eV. Using high-resolution scanning electron microscopy and Raman spectroscopy, the predominance of nanotubes with diameters from 1 to 10 nm in the array is shown. It has been revealed that HfO _2 nanocrystallization during the annealing of substrates complicates the SEM analysis of catalytic Fe particles, whose size on the surface of initial amorphous HfO _2 is 2-5 nm.

Local anode oxidation (LAO) on the Si (111) surface has been studied in the contact operational regime of an atomic force microscope (AFM) in dependence to the relative ambient humidity Θ of ( 35-75 ) % at two potentials U ( -8 and -10 V) applied to the AFM probe. It has been shown that LAO for U=-8 V occurs at Θ≥ 40% without the growth of oxide lines in width, but their height and width linearly grow at U=-10 V throughout the entire range of Θ . Based on the detailed analysis of LAO and the cantilever beam deflection in the course of probe approach to and retraction from the surface at varied Θ without probe voltage, taking into account the data on the semicontact AFM operation mode from the scientific literature, a generalized mode is proposed for the dependence of the LAO process on U and Θ .

The nonlinear splitting of magnetoelastic resonance line in powerfully excited ferrite is investigated. It is shown that the amplitude of splited resonance has the same order of value that the amplitude of basis resonance and its frequency is determined by the upper boundary of nonlinear amplitude-frequency characteristic of magnetic system. It is found the threshold character of splitting additional resonance from general. It is determined the possibility of operation of splited elastic resonance frequency by changing of exited magnetic field value which has practical importance.

Nonstationary oscillations in a system of two oscillators with a cubic connection arising in the problem of excitation of elastic vibrations in the scheme of a magnetostrictive transducer are considered. Three main oscillation modes were identified: regular beats, giant oscillations and asymmetric oscillations with a constant component. With respect to the mode of giant oscillations, it is shown that smooth oscillations are accompanied by frequent small fluctuations of small amplitude, the period of which is three orders of magnitude less than the period of the main oscillations. To interpret the observed phenomena, a model of dynamic potential is proposed, the movement of the minimum of which gives the main component of giant oscillations, and local fluctuations around the dynamic minimum provide a fine structure of frequent fluctuations.

Исследовано локальное анодное окисление (ЛАО) поверхности Si(111) в контактном режиме работы атомно-силового микроскопа (АСМ) в зависимости от относительной влажности окружающей среды Θ (35-75) % при двух потенциалах U (-8 и -10 В), приложенных к зонду АСМ. Показано, что ЛАО для U = -8 В реализуется при Θ ≥ 40 % в отсутствие роста оксидных линий в ширину, а при U = -10 В их высота и ширина линейно растут во всём интервале значений Θ. Предложена обобщённая модель зависимости процесса ЛАО от U и Θ на основе детального анализа ЛАО и изгиба балки кантилевера при подводе и отводе зонда от поверхности при вариации Θ без напряжения на зонде с учётом данных научной литературы для полуконтактного режима работы АСМ. Local anodic oxidation (LAO) of the Si(111) surface in the contact mode of an atomic force microscope (AFM) is studied depending on the relative humidity of the ambience - (35-75)% at two potentials U (-8 and -10 V) applied to the AFM probe. It is shown that LAO for U = -8V is realized at Θ ≥ 40% in the absence of growth of oxide lines in width; at U = -10V, their height and width increase linearly over the entire range of Θ values. Based on a detailed analysis of LAO and the deviation of the cantilever during the approach and retraction of the probe from the surface with variation of Θwithout voltage on the probe, taking into account literature data for the semi-contact mode of AFM operation, a generalized model of the dependence of the LAO process on U and Θis proposed.

Методом каталитического химического осаждения из газовой фазы впервые выращены массивы вертикально ориентированных углеродных нанотрубок (ВОУНТ) на поверхности Si/HfO2/Fe высотой от 25 до 100 мкм и удельным сопротивлением от 1,5 до 4 Ом · см. Рост ВОУНТ на оксиде гафния наблюдается в интервале температур 625-725 ° C, а при T ≥ 750 ° C не реализуется. При этом температурная зависимость скорости роста ВОУНТ характеризуется величиной ~1,5 эВ. С использованием высокоразрешающей сканирующей электронной микроскопии и спектроскопии комбинационного рассеяния света показано доминирующее присутствие в массиве нанотрубок с диаметрами от 1 до 10 нм. Обнаружено, что нанокристаллизация HfO2 при отжиге подложек затрудняет СЭМ-анализ каталитических частиц Fe, размер которых на поверхности исходного аморфного HfO2 составляет 2-5 нм. Using the catalytic chemical vapor deposition method, VACNT arrays with a height of 25 to 100 μm and a resistivity of 1.5 to 4 Ohm ⋅ cm have been grown for the first time on a Si/HfO2/Fe surface. The growth of VACNTs on hafnium oxide is observed in the temperature range T = 625-725°C, but is not realized at T ≥ 750 °C. In this case, the temperature dependence of the VACNT growth rate is characterized by a value of ~1.5 eV. Using high-resolution scanning electron microscopy and Raman spectroscopy, the dominant presence of nanotubes with diameters from 1 to 10 nm in the array is shown. It is found that nanocrystallization of HfO2 during annealing of substrates complicates the SEM analysis of catalytic Fe particles whose size on the surface of the initial amorphous HfO2 is 2-5 nm.

The correctness of applicability of stepped approximation for calculation the reflection, propagation and dissipation coefficients by falling the wave to multi-layer structure is investigated. The starting distribution is the linear increasing of wave number from initial to final points of structure. As an approach it is employed the presentation of structure as a combination from layers in each if it’s the wave number is constant but from one layer to other increases by stepped manner. It is formed 12 distributions with increasing fractional of distribution of structure to steps. It is shown that the dependence of reflection coefficient from the fractional distribution of structure with constant of its length has powerfully indented resonance character. It is shown that for expulsion the possibility of resonances excitation the half of minimum wave length must be more then whole length of structure. From this demand it is found the critical as so maximum value of wave number which is equal to ratio of number “pi” to the whole length of structure. It is found that the correct approximation of linear increasing by stepped is the so as which maximum of wave number is less than critical. It is found that in practice near the critical value for the achieve the correction (near 5%) it is enough the distribution of structure on seven steps which have equal high and length. When the maximum of wave number is more than critical number the anyone increasing of distribution (so as increasing of steps quantity) for increasing of approximation precision of linear structure by stepped does not achieved.

The effect of high-order uniaxial anisotropy on the nature of orientational transition of magnetization is considered. In the geometry of normal magnetization of the medium with respect to the anisotropy axis, the energy density and the equilibrium position of magnetization are obtained depending on the magnitude of the applied field. The orientation of magnetization is considered for anisotropy from the second to the eighth even orders only. As an example, the simultaneous presence of anisotropy of the second and fourth orders is considered. For this case, an algebraic equation of the third degree is obtained for the analysis of which the Cardano discriminant is used. It is shown that in the case of a negative value of the discriminant, the dependence of the magnetization orientation on the field has a hysteresis character.

A numerical study of the delay in the excitation of oscillations of a magnetostrictive transducer in the frequency multiplication mode based on the model of coupled oscillators is presented. The non-stationary nature of the oscillations excited after the amplitude jump is revealed. The phenomenon is interpreted on the basis of the dynamic potential model. A numerical study of the development of oscillations in time has been carried out, and phase portraits of oscillations have been constructed. The fractal-like nature of non-stationary oscillations is established, which manifests itself in the preservation of the degree of their chaoticity with a change in the value of the calculation step in time.

The correlation between structure configuration of carbon distribution of graphene-contained shungite and its specific electrical conductivity is investigated. The four shungite specimens from different natural depositions are investigated. The carbon structure configuration is investigated by high-permission raster electron microscopy. As a result, there was found cards of graphene layers, graphene packets and graphene ribbons along the plane of specimen surface. The specific electrical conductivity was merit be the four-contact method. On each specimen was found five cards in different its points as a whole – twenty cards. For the analysis of carbon local distribution, the descretization by three levels method was used. This method consists of applying on the card plane the grid with square cells and following analysis of regularity graphene layers by each cell. It is found three levels of order regularity structure: high, middle and low which distinguished by the number and length of graphene layers inside of cell. By averaging along all cards of present specimen for each specimen was found the own numerical characteristic which describes the carbon distribution structure. As a most important parameters were selected the averaged meaning of order degree and inversed value of square deflection from this value. It was found that the dependence of inverted value on specimen from the specimen number has the same character as the dependence on specific conductivity form the same number. As a result of investigations, it was proposed that the specific conductivity of shungite specimen may be found from statistical analysis of carbon space distribution cards which are found by the high-permission raster electron microscopy. It was proposed the algorithm of founding conductivity by analysis carbon configuration cards consisted from 16 successive steps which started from the founding the total combination of cards with the aid of electron microscope and finished by obtaining the electric conductivity value.

On the basis of generalized impedance method the propagation of single-dimension wave in multi-layer structure which contains the rectangular-type barrier is investigated. The concept of single barrier as a slide which parameters are different from the parameters of all other slides of structure is introduced. It is investigated the variation of position of real negative single barrier along the length of structure. It is found that the entrance impedance along the length of structure is varied by periodic manner. It is found the analytical formulas which simulate the dependencies of real and imaginary parts of entrance media impedances from coordinate along the structure. It is found three basis regimes which correspond to different character of oscillations: regime №1 – precise periodicity, regime №2 – break periodicity, regime №3 – monotonous increasing. It is investigated the coefficient of reflection for all mentioned above cases. It is found that the reflection coefficient from barrier displacement is not depended. It is found the periodic character of changing of amplitude and phase of reflected wave and also reflection coefficient when the height of barrier is varied. For interpretation of observed dependencies it is proposed the model of resonance inside of barrier. It is investigated the special feature of wave propagation when the barrier has complex character. It is investigated the case when the real path of wave number of barrier medium is established constant but imaginary path of the same number is varied in wide boundaries. It is established that reflection coefficient started by zero when the imaginary part of wave number is equal to zero. When imaginary part of wave number increases the reflection coefficient smooth increases in limit goes to unit. The passing coefficient also smooth decreases but more quickly then reflection coefficient and in limit goes to zero. The absorb coefficient started by zero at first smooth increases and after reaching of maximum smooth decreases in limit goes to zero. It is investigated the case when real and imaginary paths of barrier medium wave number simultaneous increase in equally proportion. It is found that in this case on the smooth curves for coefficients ob reflection, passing and absorb it is putted the oscillations. The character of oscillations is explained in the frames of resonance model.

The transformation of the trajectories of surface magnetostatic waves propagating in a ferrite film magnetized by a linearly nonuniform field caused by a high-power femtosecond laser pulse is considered. A decrease in the magnetization of the film due to an increase in its temperature can be used to account for the effect of light on wave propagation. The stepwise transformation of the trajectories of propagating waves that is synchronous with the time parameters of the femtosecond pulse is revealed. The transformation of trajectories is interpreted using the method of isofrequency curves and the Hamilton–Auld method.

The effect of high-order uniaxial anisotropy on the nature of orientational transition of magnetizationis considered. In the geometry of normal magnetization of the medium with respect to the anisotropy axis, the energy density and the equilibrium position of magnetization are obtained depending on the magnitude of the applied field. The orientation of magnetization is considered for anisotropy from the second to the eighth even orders only. As an example, the simultaneous presence of anisotropy of the second and fourthorders is considered. For this case, an algebraic equation of the third degree is obtained for the analysis of which the Cardano discriminant is used. It is shown that in the case of a negative value of the discriminant, the dependence of the magnetization orientation on the field has a hysteresis character.

The problem of excitation of ferromagnetic resonance in a thin ferrite film with magnetoelastic properties located on a thick elastic substrate is considered. A model is proposed for the excitation of elastic modes in the substrate due to the propagation of a periodic boundary regime created by magnetic oscillations in the film. The conditions for stationary oscillations are used to obtain the frequency response characteristics of ferromagnetic resonance, which exhibit strong oscillations due to the excitation of high-order elastic modes over the thickness of the substrate.

The task about the excitation of magnetoelastic vibrations in geometry of magnetostriction transducer which contains normal magnetized ferrite plate excited by alternating magnetic field is investigated. It is proposed the model presentation of transducer in the view of two connected oscillators first of its corresponds to magnetic part of structure and the second correspond to elastic its part. The first oscillator is linear and the second is nonlinear. The nonlinearity and connection have cubic character. In dependence from the excitation level it is found five basal regimes of vibrations: №1 – synchronize, №2 – three-multiplication of frequency, №3 – chaos, №4 – gigantic oscillations, №5 – delayed stabilization. In these regimes the time-evolvent of vibrations and its parametric portraits in coordinates displacement – derivative from displacement and also frequency spectra of forced vibrations are investigated. The regimes №1б №2 are stable. The vibrations in this regimes are harmonic and complete determined. The regimes №3-№5 are non-stable. The vibrations in this regimes has chaotic or near to chaotic character. On the level of excitation the stable regimes are separated from non-stable by sharp threshold. By the overcoming of which the vibration amplitude increases by sharp jump over two-three orders. By the excitation on non-stable regimes it is established the application on the main vibrations the attendant vibrations. The frequency of attendant vibrations is higher than excitation frequency on two-three orders. The amplitude of attendant vibrations is smaller than the main vibrations amplitude more then two orders. It is proposed the model of attendant vibrations excitations. On the basis of this model the quantity appreciation of vibrations character in non-stable regimes. The recommendations for future development of investigations are proposed.

The authors demonstrate the possibility of using a magnetostrictive transducer to detect a frequency-modulated microwave signal. Elastic and magnetization oscillations of a ferrite film with crystallographic anisotropy are considered. The influence of the orientation of the crystallographic cell on the dynamics of the magnetoelastic system, the establishment of various oscillations modes, and the detection process are analyzed.

The application of generalized impedance method in the variant of successive calculation of amplitude for calculation of coefficients of reflection, passage and absorption in the case of wave incidence on multi-layer structure is investigated. The slide configuration of structure is established as barrier which wave number is distributed in slides by stepped increasing manner. The forming of vibrations amplitude by different length of structure is investigated. It is shown that in the case when length of structure is less then half of maximum wave length the distribution of wave amplitude along the structure is monotony increased or decreased. In the case when length of structure is more then half of maximum wave length the distribution of wave amplitude along the structure is oscillated. The period of these oscillations is equal to the half of maximum wave length. For the medium without of dissipation the coefficient of reflection by changing of structure length is investigated. It is found the dependencies of reflection coefficient from the structure length by different meanings of maximum wave length. The coefficient of passage of wave by the changing of structure length is investigated. The reflection, passing and absorption of waves in stepped increased structure which slides have positive dissipation is investigated. It is shown that in this case the medium becomes absorbed and when the structure length is increased the absorption coefficient is also increased. The reflection, passing and absorption in medium with negative dissipation is investigated. It is mentioned that in the frame of energy balance maintained the increasing of reflection, passage and absorption by the increasing of structure length demands the additional energy from external source which in lasers is the pumping source.

The task about the excitation of magnetoelastic vibrations in geometry of magnetostriction transducer which contains normal magnetized ferrite plate excited by alternating magnetic field is investigated. The dynamics of transducer is investigated on the basis of equations system for nonlinear vibrations of two connected oscillators – magnetic and elastic. The equation for magnetic oscillator is nonlinear and for elastic oscillator – linear. The nonlinearity and connections between oscillators have cubic character. In connection with excitation level there are five basal regimes: synchronize, three-multiplication of frequency, chaos, gigantic oscillations and delayed stabilization. The first two regimes are stable, without-threshold and completely determined. The remaining three regimes are non-stable and separated form stable regimes by sharp threshold by the excitation level. It is shown that by the increasing excitation level the vibrations amplitude approach to saturation experiences in value jumps about one and half or two times. The dependence of vibrations threshold of non-stable vibrations from excitation frequency is investigated. It is shown that by increasing the excitation frequency the threshold on non-stable vibrations in very high precision increases by power low of third ore fourth order. The character of vibrations by variation of oscillator dissipation is investigated. It is found that the primary influence on the character first oscillator vibrations exercise the dissipation not first but second oscillator. The variation of own oscillators frequencies is investigated. It is shown that the increasing of own oscillator frequencies leads the system to chaos and further to regularization of vibrations. The decreasing of own oscillator frequencies leads to compressed sine with centre displaced regime and leaving of system to infinity. The variation of cubic nonlinearity of first oscillator is investigated. The large nonsymmetry of variation of vibration character by nonlinearity parameter to both sides is established. The decreasing of nonlinearity parameter leads to compressed sine with displaced centre and further leaving of system to infinity. The increasing of nonlinearity parameter leads to chaos and regularization. The variation of connection between oscillators is investigated. It is found that the variation of connection parameters any of oscillators leads to the same order of regime replacement – from regularization to chaos, gigantic oscillations, delayed stabilization, compressed sine and leaving to infinity. On the plane in coordinates first and second connection parameters the regions of existence different regimes of vibrations is constructed. For the interpretation of described phenomena the model of dynamic potential is proposed. It is shown that the potential of first oscillator has minimum the place of which is determined by value of displacement of second oscillator. The course of chaotic vibrations in non-stable regimes is the difference of phase between vibrations of oscillator and jumps of potential in which these vibrations take place. The ring character of vibrations excitation in system as a whole is considered. The analogy with autovibrations in radioengineering system with positive opposite connection is proposed. The recommendations for further development of investigation are proposed.

In this paper, we consider the problem of generation of hypersonic oscillations in the circuit of a magnetostrictive converter covered by a positive feedback circuit. A “coupling parameter” that reflects the amplification of the signal in the feedback loop was introduced. The development of magnetic and elastic oscillations in time is considered. As the coupling parameter increases, three main oscillation modes are revealed: initial relaxation, stationary self-oscillations, and chaotic self-oscillations. The effect of the coupling parameter and the damping parameter of the magnetization on the time of development and the amplitude of oscillations was studied. The characteristic values of both parameters corresponding to transitions between modes are revealed. Practical recommendations for choosing system parameters for the most efficient excitation of hypersonic oscillations are given.

The algorithm for calculation of reflection and passage of single-dimension wave through multi-layer structure which is presented as the successive one to other uniform slides is proposed. On the basis solution of single-dimension wave equation for each slide as the parameter of slide it is established the wave number. It is proposed the conception of generalized impedance for single-dimension wave which consist of propagating wave velocity relation to the frequency of the same wave. It is proposed the conception of zero-impedance of uniform region of structure which is equal to inverse value of wave number in this region. The generalized impedance is presented in the product of zero-impedance to fraction which numerator is the sum of two special solutions of wave equation for this region and denominator is the difference of the same solutions. For the calculation of reflection and passage coefficients of wave by energy for the whole structure it is found two mechanisms successive calculation along the slides of structure – successive calculation of impedances and successive calculation of amplitudes. For the mechanism successive calculation of impedances it is proposed the conceptions of entrance and exit impedances of each separately slides. It is proposed the recurrence formula which allow to found the entrance impedance of preceding medium through the entrance impedance of following medium for anyone two neighbouring regions of structure. It is established the using of this formula proposed to found the entrance impedance in initial slide of structure from the entrance impedance in last slide of structure. In this case the successive calculation of impedances is made from the end of structure to its outset. For the mechanism of successive calculation of amplitudes it is found the system consisted of two recurrence formulas which allows to found the amplitudes of straight and backward directions in preceding medium through the amplitudes the same waves in following medium. It is proposed the scheme of step-by-step successive calculation which allows from the amplitude of initial falling wave found the amplitude of reflected and passage waves relative to structure as a whole. It is mentioned the possibility and proposed the formulas which allows to found the reflection and passage coefficients on energies for the structure as a whole. It is discussed the comparative characteristics of method successive calculation of impedances and successive calculation of amplitudes.