Persons

An amplification of magnetic induction in permalloy allows a several times increase of the sensitivity of magneto-semiconductor mycrosystems magnetic field. While using the permalloy films as the magnetic concentrators, it is important to exclude the anomalous codeposition of alloy components and to reduce the variability of technological parameters for optimum magnetic properties. In the work the chloride electrolyte with the pH correction by hydrochloride acid, which provides the congruent electrochemical permalloy deposition while heating has been proposed. The magnetic properties of the permalloy films, corresponding to bulk samples, have been determined. It has been shown that the magnetic properties of the permalloy films are sensitive to deviation of the composition from the ratio of 4.26 components. The control of accuracy of preparing an electrolyte for electrochemical deposition has been performed using the spectrophotometric investigation of chloride electrolyte. It has been established that the anomaly of the permalloy electrodeposition is associated with the main feature of iron ions-the existence of variable Valence iron with two or three values in the charge of ions during the hydrolysis of ions salts.

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The magnetoresistive transducers of magnetic field have been claimed both for direct and indirect applications in various areas of industry, transport and special equipment. In the paper the special features of used terminology and dimensions in the main parameters of magnetic field magnetoresistive transformers have been revealed. The main results of experimental studies on the developed thin-film magnetoresistive nanostructures (TMN) with even and odd transfer characteristics have been presented. The TMN design on an anisotropic magnetoresistive effect has an odd transfer characteristic and conversion coefficient at the level of 8 mV/V/E. The TMN design based on a giant magnetoresistive effect has an even transfer characteristic and a conversion coefficient at the level of 27 mV/V/E. The results of promising design and technological solutions allowing reaching the values of conversion coefficient of TMN at the level exceeding 100 mV/V/E have been shown. The results of the study of the test spin-tunnel magnetoresistive nanostructure (spin-tunnel TMN) with giant magnetoresistive effect, exceeding 100% have been presented. The novelty of the obtained results has been reflected and the perspective of using highly sensitive TMN and creating the non-volatile MRAM on the basis of thin-film magnetoresistive structure with the spin-tunnel magnetoresistive effect have been determined.

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High-permeability films of CoNiFe triple system form the basis for high-density magnetic data storage. Electrochemical deposition of CoNiFe films, as contrasted with «dry» processes, gives more homogeneous coating with lesser defect level and allows reinforcing the films thickness without stresses. This study investigates the nature of the phenomena taking place at electrochemical deposition of CoNiFe films and leading to the difference in the relative content of the elements in the electrolyte and in the film. The hydrogen exponent of chloride electrolytes was examined in the temperature range of 25-70 °C and electrochemical deposition of CoNiFe films at 70 °C was studied. It was demonstrated that CoCl, NiCl, FeCl salt solutions with concentration from 0,006 to 1 mole/l are characterized by complex process of ion balance formation in single and mixed solutions. The deposition of CoNiFe films was carried out from chloride electrolyte with a component content ratio of 1:1:1 at an average concentration of 0,083 mole/l of each component. It has been established that the content of the component in the film at electrochemical deposition of three-component solution CoCl, NiCl, FeCl with equal concentration of each component did not correspond to the composition of the electrolyte but was closest to the composition of the electrolyte at a decrease in the concentration of each component at high current density.

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The problems of finite-element modeling the performance characteristics of SOI-based MEMS actuators using the applied programs have been considered. The calculation results of the MEMS actuator structure for a wide frequency range have been presented. It has been shown that due to an increase of the applied constant voltage to the control electrodes the growth of the active capacitance and the decrease of the parasitic one occur, besides, the drift of the gain-frequency characteristic shifts to the low-frequency region.

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The semiconductor gas sensors with low power consumption have high sensitivity and fast response and their manufacturing technologies permit to reduce the dimensions of the transducer. In production of the semiconductor gas sensors the formation of metal-oxide sensitive layer is an important issue, in particular, the process of combination of the high-porous metal-oxide layer and integrated structures. In the paper, the results of the study on experimental transducers of the composition of gas with porous gas-sensitive layer have been presented. The gas-sensitive layer has been formed by the method of suspension inkjet printing of SnO based suspension with further annealing. The comparison of the sensitivity of the experimental samples of the gas composition transducers with the gas-sensitive layers, formed from two variants of initial suspension: based on pure SnO and SnO doped with Cr and Nb, has been performed. The dependence of variation of conductivity of the gas composition of the integrated transducer specimen on the H concentration in the air has been obtained. It has been found that the gas-sensitive layer based on SnO with Cr and Nb additives has higher sensitivity to changes in the detected gas concentration due to higher effective surface area and suppressed grains agglomeration.

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A design and size of the membrane module package have a significant impact on its characteristics. It is necessary to use the finite element modeling calculation of the frequency response of the membrane module membrane due to complexity of the package design. In this study the method of the thin dielectric membrane modeling by means of the structural and acoustic analysis in the ANSYS software has been proposed. This method permits to perform the calculation taking into account the influence of the front and back chambers sizes. The dependences of resonance frequency of the front chamber and back chamber on its geometric sizes have been obtained. It has been shown that with the back chamber size increasing, the value of the membrane sensitivity approaches to its parameters in the open space and with the account of the front and back chambers. The membrane modules frequency response comparison has been performed and has been shown that the presence of the front and back chambers significantly affects the values of the resonance frequency and sensitivity. The method of setting resilient stresses in the membrane using thermal impact has been used. The complicatedly deformed state of the membrane, called the buckling effect, has been obtained. The calculation of the dielectric membrane with an account of the buckling effect has been executed. The analysis of the obtained results has been performed and it has been shown that the calculated sensitivity of the membrane with an account of the buckling effect have a good coincidence with the measurements results. The proposed method enables to calculate the membrane module frequency response with an account of impact of the package design peculiarities and also, to take into account the residual stresses in the membrane. The use of the structural-acoustic analysis enables to achieve more accurate results while calculating the membrane frequency response, which increases the efficiency of the acoustic pressure transducers designing, and ensures an achievement of the product optimal characteristics.

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The structural and technological solutions to create the magnetosemiconductor components for wireless microsystem magnetoresistive magnetic field measurements as well as the study results for a high-sensitivity magnetoresistive transducer with a magnetic field concentrator have been presented. The characteristics of the instrumentation amplifier designed for use with the low-impedance signal from the magnetoresistive bridge, having a certain amount of its imbalance, have been given. The combined technology of manufacturing magnetosemiconductor IC based on the thin-film magnetoresistive structures has been described.

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The results of the development of technologies for magnetic semiconductor chips based on thin-film magnetoresistive multilayer nanostructures are presented. A brief overview of the main achievements in the field of magnetometric devices based on anisotropic and giant magnetoresistive effect is made.

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The results of the study on the parameters of permalloy films, produced by the electrochemical deposition in the local areas, limited by the photoresist mask on metallic surface of silicon wafer, have been presented. The experimental dependencies of magnetic parameters of the deposited permalloy on the electrolyte excerpt time have been obtained. The possibility of application of the deposited films as the magnetic field screens of the digital isolators with galvanic separation on the basis of magnetic nanostructures has been shown.

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The results of the study on the local electrochemical deposition from chloride electrolyte have been presented and the permalloy films NiFe with magnetic properties, similar to 3-d models with the uniform thickness and with low mechanical stresses without high-temperature annealing have been obtained. The dependencies of the congruent deposition velocity on the current density have been presented. The peralloy films are designed to enhance the magnetic field in the magneto-semiconductor microsystems.

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