Thick silicon carbide films were grown on sapphire (0001) and silicon (111) substrates using metal organic chemical vapor deposition (MOCVD). Diethylmethylsilane (DEMS) has been used as a single precursor, which contain Si and C atoms in the same molecule, without any carrier or bubbler gas. Atomic structure, surface composition and morphology have been investigated by XRD, AES, SEM and AFM analysis. SiC films of 5-7 micron thickness were grown at a rate of ~ 40 nm/min on sapphire (0001) and Si (111) substrates. The films grown at low temperature (850 ºC and 900 ºC) on both substrates show crystalline 3C-SiC in the (111) orientation. XRD results show that the orientation of the crystal structure does not depend of the substrate orientation AFM pictures of SiC films grown on sapphire (0001) exhibit more crystalline order as compared to films grown on the Si (111) substrates. AES of the grown films shows that in both cases the Si peak intensity is greater than that of carbon. This work shows promise for the development of alternative processes for developing low cost, large area substrates for application to IIInitrides LED and UV photodetector fabrication and also for gas detector application.

<p>Auger electron spectroscopy (AES) has been used to investigate the chemical composition of the heteroepitaxial silicon carbide films grown on Si (100) and sapphire (0001) substrates at 900 °C by the MOCVD technique using DEMS precursor. Auger spectra were obtained from the surface and as a function of depth of 2 micron thick SiC films. AES measurements were performed under very high vacuum 10^-9 Torr conditions. Surface cleaning and depth profile studies were carried out by using Ar⁺ ion beam sputtering. Auger spectra of the surface indicate Si LVV, C KLL and O KLL peaks. The Si LVV signals on the as prepared’ surfaces for both substrates indicated that the silicon was in the oxide state, which was removed after 15 min Ar+ ion cleaning. Depth profile studies showed, that after 20 min of ion cleaning the SiC films possess near stoichiometric composition. Moreover, the C KLL signal on the ion cleaned films showed the carbon in the carbide state. X-ray diffraction analysis of the SiC films on the sapphire (0001) and Si(100) substrates has shown a high intensity single peaks at 35.7°, which indicates the presence of SiC at orientation (111).</p>

In this work, a porous nickel anode for thin-film solid oxide fuel cell prepared by the simple powder hot-pressing method is investigated. Powders of Ni and pore-forming agent (PFA) were thoroughly mixed in different ratios, pressed in a mold and further sintered. The polishing technique with Yttria-Stabilized Zirconia (YSZ) powder has been developed to decrease the surface roughness of Ni-based anode in order to deposit a crack-free electrolyte layer. The 3 μm YSZ thin-film electrolyte was deposited by the pulsed laser deposition technique on the surface of the anode. Morphological and elemental analyses of the samples were characterized by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analyses. X-ray diffraction was used for phase analysis and structural characterization. The specific surface areas of the resulting anodes were calculated from their isotherms of N2 adsorption and desorption using the Sorbtometer and calculated by Brunauer Emmett-Teller (BET) method. As a result, the highest mechanical strength and specific surface area (15.42 m2g-1) possessed a sample with the content of PFA equal to 40%, while its ionic conductivity at 800 °C reached 6. 4∙10-2 S/cm.

В настоящее время получение пористых каркасных наноструктур из проводящих материалов и полупроводников является важным направлением нанотехнологий. Пористые металлические структуры представляют растущий технологический интерес из-за множества полезных физических свойств, таких как низкая массовая плотность, высокая площадь поверхности и высокая механическая прочность. Пористые материалы также обладают потенциалом улучшения электрических, термических, оптических или реакционных свойств, что приводит к множество возможных применений. Нанопористые материалы обладают уникальными поверхностными, структурными и объемными свойствами, что приводит к применению в различных областях, таких как ионный обмен, разделение, катализ, сенсоры, биологическая молекулярная изоляция и очистка. В работе были отработаны методы получения пористых каркасных структур никеля методом селективного электрохимического травления из сплава Ni/Cu. Для установления влияния соотношения исходных компонентов (никель и медь) на морфологию пористого никеля после электрохимического травления, исследовали сплавы в следующих соотношениях Ni:Cu – 90:10,80:20 и 60:40. Было установлено, что соотношение никеля и меди в составе исходного сплава влияет на структуру и морфологию пористого никеля. Для исследования структуры и морфологии полученных образов пористого никеля были использованы современные методы анализа, такие как сканирующая электронная (растровая) микроскопия и метод низкотемпературной адсорбции азота (метод БЭТ).