Synthesis and studying properties of the GNPs@FexOy structure

An article presents a study of the regularities of the formation of gold up to 8 nm thick, deposited by vacuum thermal deposition on silicon wafers with a natural oxide, its annealing and subsequent deposition of iron oxide by chemical vapor deposition. The stages were accompanied by SEM analysis of the sample surface, as well as fixation of the optical and FTIR spectra, I–V characteristics of the obtained structures.

Evaporation of Methylammonium Iodide in Thermal Deposition of MAPbI3

Thermal evaporation is an important technique for fabricating methylammonium lead iodide (MAPbI3), but the process is complicated by the need to co-evaporate methylammonium iodide (MAI) and PbI2. In this work, the effect of water vapor during the thermal deposition of MAPbI3 was investigated under high vacuum. The evaporation process was monitored with a residual gas analyzer (RGA), and the film quality was examined with X-ray photoelectron spectroscopy (XPS). The investigations showed that during evaporation, MAI decomposed while PbI2 evaporated as a whole compound. It was found that the residual water vapor reacted with one of the MAI-dissociated products. The higher iodine ratio suggests that the real MAI flux was higher than the reading from the QCM. The XPS analysis demonstrated that the residual water vapor may alter the elemental ratios of C, N, and I in thermally deposited MAPbI3. Morphologic properties were investigated with atomic force microscopy (AFM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). It was observed that a sample grown with high water vapor pressure had a roughened surface and poor film quality. Therefore, an evaporation environment with water vapor pressure below 10−8 Torr is needed to fabricate high quality perovskite films.

Structure of Plasma (re)Polymerized Polylactic Acid Films Fabricated by Plasma-Assisted Vapour Thermal Deposition

Plasma polymer films typically consist of very short fragments of the precursor molecules. That rather limits the applicability of most plasma polymerisation/plasma-enhanced chemical vapour deposition (PECVD) processes in cases where retention of longer molecular structures is desirable. Plasma-assisted vapour thermal deposition (PAVTD) circumvents this limitation by using a classical bulk polymer as a high molecular weight “precursor”. As a model polymer in this study, polylactic acid (PLA) has been used. The resulting PLA-like films were characterised mostly by X-ray photoelectron spectroscopy (XPS) and nuclear magnetic resonance (NMR) spectroscopy. The molecular structure of the films was found to be tunable in a broad range: from the structures very similar to bulk PLA polymer to structures that are more typical for films prepared using PECVD. In all cases, PLA-like groups are at least partially preserved. A simplified model of the PAVTD process chemistry was proposed and found to describe well the observed composition of the films. The structure of the PLA-like films demonstrates the ability of plasma-assisted vapour thermal deposition to bridge the typical gap between the classical and plasma polymers.

Thermal deposition method for p–n patterning of carbon nanotube sheets for planar-type thermoelectric generator

Thermal deposition of n-dopant onto SWCNT sheet (p-type) using patterned mask can fabricate p–n patterns with high special resolution. Thermoelectric generator using patterned SWCNT sheets exhibited power density of 60 nW cm−2 at ΔT = 25 °C.

A Highly-efficient, Stable and Flexible Kapton Tape-based SERS Chip

A flexible SERS chip fully covered with silver (Ag) nanoparticles is obtained by one-step metal thermal deposition on the Kapton tape, exhibiting ultrasensitivity, high-uniformity, and especially long-term SERS stability up...

CHANGES IN THE STRUCTURE OF GOLD NANOPARTICLES ON THE TUNGSTEN SURFACE CAUSED BY HEATING

Исследовано формирование наночастиц золота на поверхности вольфрама и влияние прогрева на их структуру. Найдено, что термическое напыление атомов золота на поверхность вольфрама при комнатной температуре приводит к формированию хаотично расположенных наночастиц. Средняя площадь наночастиц составляет 10210 нм. Прогрев в течение 30 минут при температуре 600 K приводит к слиянию наночастиц, что находит отражение в увеличении средней площади наночастиц до 19520 нм. Дальнейший прогрев в течение 30 минут при температуре 600 K не приводил к увеличению средней площади наночастиц. Анализ формы наночастиц показал, что они являются эллипсоидами. Непрогретые наночастицы имеют большую полуось 110 ± 30 нм и эксцентриситет 1,5 ± 0,4. Прогрев золотых наночастиц приводит к увеличению полуоси до 200 ± 120 нм и эксцентриситета до 1,8 ± 0,6. Показано, что наночастицы после прогрева приобретают форму обрезанного эллипсоида. The formation of gold nanoparticles on the tungsten surface and the effect of heating on their structure are studied. It was found that the thermal deposition of gold atoms on the tungsten surface at room temperature leads to formation of randomly located nanoparticles. The average area of nanoparticles is 10210 nm. Heating for 30 minutes at a temperature of 600 K leads to the fusion of nanoparticles, which is reflected in an increase in the average area of nanoparticles to 19520 nm. Further heating for 30 minutes at temperature 600 K did not lead to an increase in the average area of nanoparticles. An analysis of the shape of the nanoparticles showed that they are elongated ellipsoids. Unheated nanoparticles have a semi-major axis of 110±30 nm and eccentricity 1,5 ±0,4 . Heating of gold nanoparticles leads to an increase in the semi-major axis to 200 ±120 nm and an eccentricity to 1,8 ± 0,6. It is shown that the nanoparticles after heating become a cropped ellipsoid.

Engineering Applications of Peristaltic Fluid Flow with Hall Current, Thermal Deposition and Convective Conditions

This article addresses the peristaltic flow in a compliant wall channel. Analysis has been carried out in the presence of a Hall current and chemical reaction. Convective conditions in terms of both heat and mass transfer are employed. Mathematical modeling is developed for an incompressible Carreau fluid. Thermal deposition effect and convection at the channel walls are considered. Series solutions are obtained for small Weissenberg number We. Solution expressions of velocity, temperature, concentration and stream function are obtained. These physical quantities are displayed and analyzed. Heat transfer coefficient and trapping are explored in detail.