- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Reactive wetting of binary Sn Cr alloy on polycrystalline chemical vapour deposited diamond at relatively low temperatures
摘要： Synthetic diamond has excellent mechanical, thermal, and electrical properties, which makes it an ideal material in a wide range applications from abrasive grinding tools to modern electronic devices. Hence, understanding the wettability of metals on the synthetic diamond is of great importance for the development of diamond-related materials and devices. In this study, the wettability and spreading kinetics of binary SneCr alloy on chemical vapour deposed (CVD) polycrystalline diamond compacts were investigated using a sessile drop method. In situ observation of contact angle at elevating temperatures indicated trace addition of Cr dramatically improved the wettability of Sn on CVD diamond, and the SneCr alloy started to wet CVD diamond at approximately 750 °C. Isothermal spreading kinetic analysis revealed that the spreading of SneCr alloy on CVD diamond was controlled by the kinetics of chemical reaction at advancing triple line. Microstructure characterization indicated that the formation of nano-sized scallop-like Cr7C3 grains was responsible for the improved wettability of SneCr alloy on CVD diamond substrate. The wetting temperature was found to play a determinant role in the interfacial carbide formation, and hence the reactive wetting of SneCr alloy on CVD diamond at temperatures from 700 to 900 °C.
关键词： Reactive wetting,Interface reaction,Chromium carbides,CVD diamond
更新于2025-09-19 17:15:36
-
Synthesis of Silver Sulfide Quantum Dots Via the Liquid–Liquid Interface Reaction in a Rotating Packed Bed Reactor
摘要： We developed the high-gravity coupled liquid–liquid interface reaction technique on the basis of the rotating packed bed (RPB) reactor for the continuous and ultrafast synthesis of silver sulfide (Ag2S) quantum dots (QDs) with near-infrared (NIR) luminescence. The formation of Ag2S QDs occurs at the interface of microdroplets, and the average size of Ag2S QDs was 4.5 nm with a narrow size distribution. Ag2S QDs can disperse well in various organic solvents and exhibit NIR luminescence with a peak wavelength at 1270 nm under 980-nm laser excitation. The mechanism of the process intensification was revealed by both the computational fluid dynamics simulation and fluorescence imaging, and the mechanism is attributed to the small and uniform droplet formation in the RPB reactor. This study provides a novel approach for the continuous and ultrafast synthesis of NIR Ag2S QDs for potential scale-up.
关键词： Liquid–liquid interface reaction,Rotating packed bed,Ag2S quantum dots,Near-infrared luminescence,Process intensification
更新于2025-09-12 10:27:22
-
Nondestructive characterization of the polycarbonate - octadecylamine interface by surface enhanced Raman spectroscopy
摘要： Polymer composite materials are used increasingly in material and engineering science. They provide outstanding mechanical and optical properties. The linkage between the polymer materials is crucial for achieving the desired properties. Understanding the linkage and structure of the polymer-polymer interface layer is a key for utilization polymer composite materials as well as for their fabrication. When analyzing the thin polymer-polymer interface it is important to achieve clear identification of molecular linker structures. One reliable analytical technique allowing this is surface enhanced Raman scattering (SERS) spectroscopy. This study aims at the in-situ evaluation of SERS spectra recorded from the Polycarbonate (PC) –Octadecylamine (ODA) interface to identify the formation of urethane bonds. The detailed analysis of SERS spectra taken before and after the chemical linkage reaction reveals the formation of urethane structures, indicating a chemical bond between PC and ODA. The spectral pattern of urethane groups was identified and evaluated by a reference Raman spectrum.
关键词： SERS,Polymer interphase,Aminolysis,Polycarbonate,Interface reaction
更新于2025-09-10 09:29:36
-
[IEEE 2018 Open Innovations (OI) - South Africa (2018.10.3-2018.10.5)] 2018 Open Innovations Conference (OI) - Phase Formation Between Iridium Thin Films and Zirconium Carbide Prepared by Spark Plasma Sintering at Relatively Low Temperatures
摘要： Zirconium carbide (ZrC) samples were prepared by spark plasma sintering (SPS), at temperatures of 1700 °C, 1900 °C and 2100 °C at 50 MPa for 10 minutes. The phase and microstructure after the sintering process was investigated. The relative density of ZrC ceramic pellets formed at 1700 °C, 1900 °C and 2100 °C was measured and found to be 96.5 %, 98.9 % and 99.5 % respectively. The grain size of ZrC ceramic pellets was calculated and it was found to increase from 71.88 nm, 79.15 nm and 83.59 nm as the sintering temperature increased from 1700 oC, 1900 oC to 2100 oC respectively. The hardness of ZrC ceramic pellets was found to be 7.40 GPa, 17.00 GPa to 18.40 GPa at 1700 oC, 1900 oC to 2100 oC respectively. The preferred orientation at 1700 oC, 1900 oC and 2100 oC was the (200) plane. Iridium (Ir) thin films were deposited on ZrC ceramics by electron beam deposition method and annealed in vacuum at temperatures of 600 °C and 800 °C for 2h. The phase composition, solid-state reactions and surface morphology were investigated by grazing incidence x-ray diffraction (GIXRD), and scanning electron microscopy (SEM). XRD was used to identify the phases present in the as-deposited and annealed samples. XRD analysis showed that Ir2Zr was the initial phase formed at 600 °C. At temperature 800 °C, Ir reacted with the ZrC to form IrZr. The SEM images of as-sintered samples at 1700 oC, 1900 oC and 2100 oC showed that the ZrC surface was heterogeneous and uneven consisting of agglomerated granules with a few pores. The number of pores was observed to reduce with sintering temperature. After depositing Ir films on ZrC substrate, the structure of the Ir film followed that of the substrates. After annealing the Ir-ZrC samples at 600 oC and 800 oC, the further agglomeration of surface granules was observed.
关键词： morphology,interface reaction,Zirconium carbide,SPS,iridium
更新于2025-09-09 09:28:46
-
Reactivity studies and structural properties of Al on compound semiconductor surfaces
摘要： The authors studied the structural properties of Al on III-V semiconductors (InAs, GaAs, and InGaAs) with the aim of creating smooth and abrupt interfaces. Growth conditions, such as the residual As content and the presence of intermediate layers, affect the structural properties of the Al and the underlying semiconductor. The authors find that an ultrathin layer of AlAs on (001) InAs drastically reduces the interface reaction and improves the epitaxial growth of Al. No such layer is necessary for interface reaction mitigation for Al deposited onto InGaAs or GaAs. The crystal orientation of Al planes grown on (001) InAs is [110], but is [111] on InGaAs or GaAs. The authors discuss the significance of the results for realization of structures for proximity superconductivity.
关键词： GaAs,InAs,Al,epitaxial growth,proximity superconductivity,InGaAs,interface reaction,III-V semiconductors
更新于2025-09-04 15:30:14