Multicomponent Sn–Mo–O-containing films formed in anodic alumina matrixes by ionic layer deposition

Multicomponent metal oxide compounds of the composition Sn–Mo–O, Sn–Ni–Mo–O and Sn–Bi–Mo–O were formed by successive ionic layer adsorption and reaction (SILAR) method deposition into anodic alumina matrixes. The growth mechanism of the Sn–Mo–O-containing films in the porous anodic alu- mina was investigated. It was found that the degree of pore filling, specific thickness and surface mor- phology of the deposited layer depend not only on the number of cycle’s treatment, but also on the composition of the used solutions. The morphology of Sn–Mo–O and Sn–Ni–Mo–O surfaces had granular structures, while Sn–Bi–Mo–O layer had flake-like structure. The differences in microstructure and depo- sition of the layers on the surface of the matrixes can be explained by the insufficient activation of anodic alumina pores before deposition. The investigations of the formed layers composition by the electron- probe X-ray spectral microanalysis showed that the ratio of tin to molybdenum in tin-molybdenum con- taining oxides changes. The Sn/Mo atomic ratio for Sn–Mo–O layer is 1.29/2.72; for Sn–Ni–Mo–O layer is 5.83/4.85; for Sn–Bi–Mo–O layer is 0.60/0.87. The using of SILAR method allows forming multicomponent films in the anodic alumina matrixes, which have great potential to applicate in high-sensitivity gas sensors

Formation of multicomponent matrix metal oxide films in anodic alumina matrixes by chemical deposition

The metal oxide films of Sn[x]Zn[y]O[z] and Sn[x]Mo[y]O[z] systems deposited onto anodic alumina matrixes by chemical and ion layering from an aqueous solutions were characterized by scanning electron microscopy, Raman spectroscopy, electron probe X-ray microanalysis and IR spectroscopy. The obtained matrix films had reproducible composition and structure and possessed certain morphological characteristics and properties

Anodic Niobia Column-like 3-D Nanostructures for Semiconductor Devices

Two types of anodic niobia (niobium oxide) column-like three-dimensional (3-D) nanostructures were synthesized by anodization in 0.4 mol•dm -3 oxalic acid aqueous solution at 37 V, reanodizing in 1% citric acid aqueous solution up to 300 and 450 V, and chemical etching of magnetron sputter-deposited Al/Nb metal layers. The dependence of the synthesized niobia column-like 3-D nanostructures' morphological properties on formation conditions were defined by scanning electron microscopy. The niobia column-like 3-D nanostructures' electrophysical characteristics were investigated in two measurement schemes. Aluminum layers of 500-nm thickness were used as contact pads. The current-voltage characteristic (I-V) has nonlinear and nonsymmetrical character. The nonsymmetrical I-V reached ~10 V. The breakdown voltages were 80 and 125 V, self-heating begins at voltage direct connection 33 and 60 V, initial resistance at 23 °C was 60 and 120 kΩ, specific resistance to the height of the columns was 87 and 116 Ω•nm -1 , and the calculated temperature coefficient of resistance in the range 20-105 °C appeared to be negative and rather low, -1.39•10 -2 and -1.28•10 -2 K -1 , for the niobia column-like 3-D nanostructures reanodized at 300 and 450 V, respectively

Columnar Niobium Oxide Nanostructures: Mechanism of Formation, Microstructure, and Electrophysical Properties

The morphology and microstructure of columnar niobium oxide nanostructures are studied and the dependences of their morphological sizes on anodizing voltages (100–450 V) and anodic alumina pore diameters (40–150 nm) are established. The features of ion transport during local anodization of niobium are studied and the transport numbers of electrolyte anions and niobium cations are calculated; a mechanism of formation and growth is proposed and the phase composition and electrophysical properties of columnar nanostructures are studied

Конструкционные упрочняющие композитные покрытия на алюминиевых сплавах из матричных углеродных и металлоксидных наноструктур

Использование современных конструкционных материалов обычно ограничивается тем, что увеличение прочности приводит к снижению пластичности. Однако более глубокое изучение физики деформационных процессов наноструктурированных материалов показало, что уменьшение их микроструктуры и наноструктурирование приводят к появлению в них новых качеств и созданию новых видов материалов с повышенной прочностью и пластичностью. Проведенные исследования при разработке конструкционных композитных покрытий с наполнителями из матричных наноструктур на основе металлооксидных и углеродных материалов показали перспективы для их применения в качестве упрочняющих покрытий на алюминии при изготовлении литых изделий точной формы из цветных сплавов с повышенной износостойкостью и ударной вязкостью, создании наноструктурированных защитных термо- и коррозионностойких покрытий, обладающих повышенной прочностью и низкой воспламеняемостью

Synthesis of matrix nanostructures from oxides and sulfides of transition metals

An original technology for the formation of spatially ordered planar TiO2/Bi2O3 and TiO 2 /CdS nanosystems is proposed, which based on the electrochemical anodization of titanium through anodic alumina mask and ionic cyclic layering of composite films based on Bi2O3 and chemical deposition of CdS on nanostructured TiO 2 surface. Comprehensive studies of multicomponent composites with three-dimensional architecture specified for practical use have been carried out, and prospects for the creation of effective photovoltaic and sensoric devices on their basis have been determined

A Micropowered Chemoresistive Sensor Based on a Thin Alumina Nanoporous Membrane and SnxBikMoyOz Nanocomposite

This work presents and discusses the design of an efficient gas sensor, as well as the technological process of its fabrication. The optimal dimensions of the different sensor elements including their deformation were determined considering the geometric modeling and the calculated moduli of the elasticity and thermal conductivity coefficients. Multicomponent SnxBikMoyOz thin films were prepared by ionic layering on an anodic alumina membrane and were used as gas-sensitive layers in the sensor design. The resistance of the SnxBikMoyOz nanostructured film at temperatures up to 150 ◦C exceeded 106 Ohm but decreased to 104 Ohm at 550 ◦C in air. The sensitivity of the SnxBikMoyOz composite to concentrations of 5 and 40 ppm H2 at 250 ◦C (10 mW) was determined to be 0.22 and 0.40, respectively

Матричные наносистемы на основе оксида висмута для рентгеноконтрастной диагностики и защиты от ионизирующего излучения

The features of the bismuth oxide deposition by the ion layering method on matrices of anodic alumina and anodic titania have been studied. The formed nanostructured systems have been studied by means of electron micros copy, X-ray microanalysis, and X-ray spectroscopy. Two-layer nanocomposites consist of porous matrix or TiO2 island film with vertically oriented Bi2O3 plates placed on the surface. The photoluminescence spectrum of Al2O3/Bi2O3 oxide structure contains two photoluminescence channels with peaks at 460 and 560 nm upon excitation at 345 nm. Analysis of the EDX spectra showed that the atomic ratio of Bi, Ti and O was 31.46 % Bi : 3.78 % Ti : 51.05 % O. The possibility of using complex nanocomposite as contrast agents in X-ray diagnostics and for protection against ionizing radiation is shown.Исследованы особенности нанесения оксида висмута на матрицы анодного оксида алюминия и оксида титана методом ионного наслаивания. Сформированные наноструктурированные системы изучены с помощью электронной микроскопии, рентгеновского микроанализа и рентгеновской спектроскопии. Нанокомпозиты представляют собой двухслойные системы из пористой матрицы или островковой пленки TiO2, на поверхности которых находятся вертикально ориентированные пластинки Bi2O3. В спектре фотолюминесценции структуры Al2O3/Bi2O3 присутствуют два канала фотолюминесценции с пиками на 460 и 560 нм при 345 нм возбуждения. Анализ EDX-спектров показал, что атомарное соотношение Bi, Ti и O составило 31,46 % Bi : 3,78 % Ti : 51,05 % O. Показана возможность использования сложного нанокомпозита в качестве контрастирующего агента в рентгеновской диагностике и для защиты от ионизирующего излучения

Features of electrochemical formation of metal and semiconductor nanowires in anodic alumina matrices with variable pores

Methods for the porous membranes formation from anodic alumina with periodically alternating pore diameters along the membrane depth and the electrochemical nanowires formation of complex morphology from various materials have been developed and tested. The features of the electrochemical deposition of indium and copper antimonide into pores with varying diameters under different chemical conditions and electrical modes have been investigated. The electron microscopic studies of the created nanosystems have been carried out, the elemental composition has been investigated, the current-voltage characteristics of InSb nanowires of complex morphology have been measured