Monitoring of Electrode Temperature in Exothermic Electrochemical Process

In this paper the features of temperature control of aluminum electrode during the anodization are discussed. Temperature monitoring in this exothermic process is a necessary condition for obtaining a high ordered nanoporous structure. A new electrochemical cell with a Peltier device working in cooling or heating mode was proposed. Time dependences of the electrolyte and Peltier element temperatures without and during anodizing process were presented. The results demonstrated that the cell construction allows precise control of the electrode temperature

Study of microstructure of porous anodic alumina films formed in malonic acid in the wide range of aluminium anodizing voltages

In present paper the microstructure parameters of porous anodic alumina films formed by the anodizing of aluminum in the aqueous solution of malonic acid at different anodizing voltages was studied. The morphology of structured surface of aluminum film was studied using a scanning electron microscope after selective removal of anodic film. The results obtained for anodic films formed in malonic acid during anodizing in the range of 15-80 V allowed to determine that change in the interpore distance with the anodizing voltage is linear function with a slope of 1.45. The key conclusion was made that mechanical stress in anodic alumina layer is the main factor responsible for formation of the nanoporous structure of anodic alumina films

КОМПЬЮТЕРНОЕ МОДЕЛИРОВАНИЕ И ИССЛЕДОВАНИЕ ХАРАКТЕРИСТИК ОТРАЖЕНИЯ РЕЗОНАНСНЫХ ДИЭЛЕКТРИЧЕСКИХ СТРУКТУР ДЛЯ ЭЛЕКТРОМАГНИТНЫХ ЭКРАНОВ

The results of computer simulation and investigation of reflectance spectra of resonance in the range of 7…13 GHz for insulator structures consisted of lithium niobate and anodic alumina with thin nichrome film are presented.Приведены результаты компьютерного моделирования и изучения спектров отражения в диапазоне частот 7…13 ГГц для резонансных диэлектрических структур, состоящих из ниобата лития и анодного оксида алюминия с напыленной пленкой нихрома

Obtaining, properties and application of nanoscale films of anodic titanium dioxide on Ti-Al films for perovskite solar cells

The modes of synthesis of TiO2 films with semiconducting properties by the method of electrochemical oxidation of Ti are proposed for use as an electronic transport layer of perovskite solar cells. To anodize the titanium film, the electrolyte based on a mixture of a 2 % aqueous solution of oxalic acid and a 1 % aqueous solution of sulfamic acids was used. The results obtained showed that Al and Ni have injection contacts to the anodic TiO2 films. Nanoscale titanium oxide films have low resistivity and rectilinear and symmetric I - V characteristic branches. Annealing of titanium oxide films leads to a significant decrease in the resistivity

Engineering of III-Nitride Semiconductors on Low Temperature Co-fired Ceramics

This work presents results in the feld of advanced substrate solutions in order to achieve high crystalline quality group-III nitrides based heterostructures for high frequency and power devices or for sensor applications. With that objective, Low Temperature Co-fred Ceramics has been used, as a noncrystalline substrate. Structures like these have never been developed before, and for economic reasons will represent a groundbreaking material in these felds of Electronic. In this sense, the report presents the characterization through various techniques of three series of specimens where GaN was deposited on this ceramic composite, using diferent bufer layers, and a singular metal-organic chemical vapor deposition related technique for low temperature deposition. Other single crystalline ceramic-based templates were also utilized as substrate materials, for comparison purposes

Pore formation in highly ordered anodic alumina templates controlled by the rate of electrolyte stirring at the oxide surface

This paper presents the studies on the cooling of the aluminum surface during its anodization by controlling the rate of electrolyte stirring and its effect on the morphology of the nanoporous anodic films. The obtained data demonstrates the possibility to control the pore diameter during the anodizing process without changing the anodizing voltage and interpore distance. This allows a higher utilization factor of the anode oxide when it is used as a matrix to obtain metal nanowires

COMPUTER SIMULATION AND INVESTIGATION OF REFLECTANCE CHARACTERISTICS OF RESONANCE INSULATOR STRUCTURERS FOR SHIELDS OF ELECTROMAGNETIC RADIATION

The results of computer simulation and investigation of reflectance spectra of resonance in the range of 7…13 GHz for insulator structures consisted of lithium niobate and anodic alumina with thin nichrome film are presented

Interconnections formation at bilateral surface mount technology

Исследован процесс формирования межсоединений расплавлением бессвинцовой паяльной пасты при кондуктивном и конвекционном нагреве для плат с двухсторонним поверхностным монтажом. Установлено, что при лазерном сверлении отверстий диаметром менее 300 мкм и применении бессвинцовой паяльной пасты возможен переход на нижележащий уровень непосредственно под контактной площадкой.Process of interconnections formation by fusion Pb–free soldering pastes is investigated at conductive and convection heating for payments with bilateral surface mount technology. It is established, that at laser drilling apertures in diameter less than 300 microns and application Pb–free soldering pastes transition to a under laying level under a contact platform is possible

Effect of Aluminum Anode Temperature on Growth Rate and Structure of Nanoporous Anodic Alumina

In the present study, we investigated the effect of an anode temperature on current transient process during porous anodic alumina growth and morphology of the anodic layers. Alumina films were formed in a 0.4 M oxalic acid at a constant voltage mode and electrolyte temperature. The temperature of the Al anode was controlled by thermoelectric Peltier element and varied in the range of 5 °C–60 °C. Surface morphology of both sides of anodic films and their cross-sections were analyzed by scanning electron microscopy (SEM) with subsequent statistical analysis of the SEM images by ImageJ software. It was found that when anode temperature was increased from 5 °С to 50 °С the pores diameter and interpore distance has not changed, but the porous structure became more ordered. According to these results, the rate of chemical dissolution of the barrier layer and pore walls did not depend on the anode temperature. At the anode temperature of 60 °С, pores diameter has increased 1.7 times and there was a distortion of the ordering of porous cells. It was concluded that the temperature difference between the aluminum substrate and electrolyte is an important parameter affecting the formation of ordered structure of nanoporous anodic alumina