Structural and Electronic Studies of C60 Films Deposited Using a New Technique of Neutral Cluster Beam Deposition

1994 ◽  
Vol 349 ◽  
Author(s):  
Zhong-Min Ren ◽  
Zhi-Feng Ying ◽  
Xia-Xing Xiong ◽  
Mao-Qi He ◽  
Yuan-Cheng Du ◽  
...  

ABSTRACTC50 films, are deposited on Si(111) substrates using neutral cluster beams of fullerenes generated from a crucible with a special nozzle. X-ray diffraction (XRD) have been used to investigate the structural properties of C50 films, which indicate highly textural films as close-packed structure with strong (110) XRD assignment and 400Å for correlation length. Raman spectrum indicates the existence of stable C60 films. X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) measurements are carried out to analyze the electronic properties of the films. The resistivity to contamination of C50 film deposited here is better than that deposited by MBE. Different kinds of oxygen contamination on the surfaces of C50 films and HDPG are detected by the results of O 1s XPS analyses.

2005 ◽  
Vol 876 ◽  
Author(s):  
Patrick Huber ◽  
Klaus Knorr

AbstractWe present a selection of x-ray diffraction patterns of spherical (He, Ar), dumbbell- (N2, CO), and chain-like molecules (n-C9H20, n-C19H40) solidified in nanopores of silica glass (mean pore diameter 7nm). These patterns allow us to demonstrate how key principles governing crystallization have to be adapted in order to accomplish solidification in restricted geometries. 4He, Ar, and the spherical close packed phases of CO and N2 adjust to the pore geometry by introducing a sizeable amount of stacking faults. For the pore solidified, medium-length chainlike n-C19H40 we observe a close packed structure without lamellar ordering, whereas for the short-chain C9H20 the layering principle survives, albeit in a modified fashion compared to the bulk phase.


2014 ◽  
Vol 1603 ◽  
Author(s):  
Mitsuki Nakashima ◽  
Toshiyuki Yamaguchi ◽  
Masanobu Izaki

ABSTRACTCu2ZnSnSe4 thin films were prepared by using the synthesized Cu2ZnSnSe4 ingot and Na2Se powder at various Na2Se/Cu2ZnSnSe4 mole ratio as evaporation materials for selenization process. From EPMA analysis, the composition was approximately constant even if the Na2Se/Cu2ZnSnSe4 mole ratio increased. X-ray diffraction studies revealed that the thin films had a kesterite Cu2ZnSnSe4 structure and the foreign phases disappeared with increasing the Na2Se/Cu2ZnSnSe4 mole ratio. The Na2Se addition enhanced to grow thin films having a close-packed structure and columnar grains. The values of Voc and Isc in Cu2ZnSnSe4 thin film solar cells increased with increasing the Na2Se/Cu2ZnSnSe4 mole ratio.


2003 ◽  
Vol 780 ◽  
Author(s):  
C. Essary ◽  
V. Craciun ◽  
J. M. Howard ◽  
R. K. Singh

AbstractHf metal thin films were deposited on Si substrates using a pulsed laser deposition technique in vacuum and in ammonia ambients. The films were then oxidized at 400 °C in 300 Torr of O2. Half the samples were oxidized in the presence of ultraviolet (UV) radiation from a Hg lamp array. X-ray photoelectron spectroscopy, atomic force microscopy, and grazing angle X-ray diffraction were used to compare the crystallinity, roughness, and composition of the films. It has been found that UV radiation causes roughening of the films and also promotes crystallization at lower temperatures.Furthermore, increased silicon oxidation at the interface was noted with the UVirradiated samples and was shown to be in the form of a mixed layer using angle-resolved X-ray photoelectron spectroscopy. Incorporation of nitrogen into the film reduces the oxidation of the silicon interface.


Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 581
Author(s):  
Gajanan S. Ghodake ◽  
Surendra K. Shinde ◽  
Ganesh D. Saratale ◽  
Rijuta G. Saratale ◽  
Min Kim ◽  
...  

The utilization of waste-paper-biomass for extraction of important α-cellulose biopolymer, and modification of extracted α-cellulose for application in enzyme immobilization can be extremely vital for green circular bio-economy. Thus, in this study, α-cellulose fibers were super-magnetized (Fe3O4), grafted with chitosan (CTNs), and thiol (-SH) modified for laccase immobilization. The developed material was characterized by high-resolution transmission electron microscopy (HR-TEM), HR-TEM energy dispersive X-ray spectroscopy (HR-TEM-EDS), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR) analyses. Laccase immobilized on α-Cellulose-Fe3O4-CTNs (α-Cellulose-Fe3O4-CTNs-Laccase) gave significant activity recovery (99.16%) and laccase loading potential (169.36 mg/g). The α-Cellulose-Fe3O4-CTNs-Laccase displayed excellent stabilities for temperature, pH, and storage time. The α-Cellulose-Fe3O4-CTNs-Laccase applied in repeated cycles shown remarkable consistency of activity retention for 10 cycles. After the 10th cycle, α-Cellulose-Fe3O4-CTNs possessed 80.65% relative activity. Furthermore, α-Cellulose-Fe3O4-CTNs-Laccase shown excellent degradation of pharmaceutical contaminant sulfamethoxazole (SMX). The SMX degradation by α-Cellulose-Fe3O4-CTNs-Laccase was found optimum at incubation time (20 h), pH (3), temperatures (30 °C), and shaking conditions (200 rpm). Finally, α-Cellulose-Fe3O4-CTNs-Laccase gave repeated degradation of SMX. Thus, this study presents a novel, waste-derived, highly capable, and super-magnetic nanocomposite for enzyme immobilization applications.


Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 346
Author(s):  
Sonam Goyal ◽  
Maizatul Shima Shaharun ◽  
Ganaga Suriya Jayabal ◽  
Chong Fai Kait ◽  
Bawadi Abdullah ◽  
...  

A set of novel photocatalysts, i.e., copper-zirconia imidazolate (CuZrIm) frameworks, were synthesized using different zirconia molar ratios (i.e., 0.5, 1, and 1.5 mmol). The photoreduction process of CO2 to methanol in a continuous-flow stirred photoreactor at pressure and temperature of 1 atm and 25 °C, respectively, was studied. The physicochemical properties of the synthesized catalysts were studied using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) spectroscopy. The highest methanol activity of 818.59 µmol/L.g was recorded when the CuZrIm1 catalyst with Cu/Zr/Im/NH4OH molar ratio of 2:1:4:2 (mmol/mmol/mmol/M) was employed. The enhanced yield is attributed to the presence of Cu2+ oxidation state and the uniformly dispersed active metals. The response surface methodology (RSM) was used to optimize the reaction parameters. The predicted results agreed well with the experimental ones with the correlation coefficient (R2) of 0.99. The optimization results showed that the highest methanol activity of 1054 µmol/L.g was recorded when the optimum parameters were employed, i.e., stirring rate (540 rpm), intensity of light (275 W/m2) and photocatalyst loading (1.3 g/L). The redox potential value for the CuZrIm1 shows that the reduction potential is −1.70 V and the oxidation potential is +1.28 V for the photoreduction of CO2 to methanol. The current work has established the potential utilization of the imidazolate framework as catalyst support for the photoreduction of CO2 to methanol.


Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 937
Author(s):  
Yingying Hu ◽  
Md Rasadujjaman ◽  
Yanrong Wang ◽  
Jing Zhang ◽  
Jiang Yan ◽  
...  

By reactive DC magnetron sputtering from a pure Ta target onto silicon substrates, Ta(N) films were prepared with different N2 flow rates of 0, 12, 17, 25, 38, and 58 sccm. The effects of N2 flow rate on the electrical properties, crystal structure, elemental composition, and optical properties of Ta(N) were studied. These properties were characterized by the four-probe method, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and spectroscopic ellipsometry (SE). Results show that the deposition rate decreases with an increase of N2 flows. Furthermore, as resistivity increases, the crystal size decreases, the crystal structure transitions from β-Ta to TaN(111), and finally becomes the N-rich phase Ta3N5(130, 040). Studying the optical properties, it is found that there are differences in the refractive index (n) and extinction coefficient (k) of Ta(N) with different thicknesses and different N2 flow rates, depending on the crystal size and crystal phase structure.


2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Valentina Krylova ◽  
Mindaugas Andrulevičius

Copper sulfide layers were formed on polyamide PA 6 surface using the sorption-diffusion method. Polymer samples were immersed for 4 and 5 h in 0.15 mol⋅  solutions and acidified with HCl (0.1 mol⋅) at . After washing and drying, the samples were treated with Cu(I) salt solution. The samples were studied by UV/VIS, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) methods. All methods confirmed that on the surface of the polyamide film a layer of copper sulfide was formed. The copper sulfide layers are indirect band-gap semiconductors. The values of are 1.25 and 1.3 eV for 4 h and 5 h sulfured PA 6 respectively. Copper XPS spectra analyses showed Cu(I) bonds only in deeper layers of the formed film, while in sulfur XPS S 2p spectra dominating sulfide bonds were found after cleaning the surface with ions. It has been established by the XRD method that, beside , the layer contains as well. For PA 6 initially sulfured 4 h, grain size forchalcocite, , was  nm and fordjurleite, , it was 54.17 nm. The sheet resistance of the obtained layer varies from 6300 to 102 .


Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 48
Author(s):  
Pawel Mierczynski ◽  
Magdalena Mosińska ◽  
Lukasz Szkudlarek ◽  
Karolina Chalupka ◽  
Misa Tatsuzawa ◽  
...  

Biodiesel production from rapeseed oil and methanol via transesterification reaction facilitated by various monometallic catalyst supported on natural zeolite (NZ) was investigated. The physicochemical characteristics of the synthesized catalysts were studied by X-ray diffraction (XRD), Brunauer–Emmett–Teller method (BET), temperature-programmed-reduction in hydrogen (H2-TPR), temperature-programmed-desorption of ammonia (NH3-TPD), Scanning Electron Microscope equipped with EDX detector (SEM-EDS), and X-ray photoelectron spectroscopy (XPS) methods. The highest activity and methyl ester yields were obtained for the Pt/NZ catalyst. This catalyst showed the highest triglycerides conversion of 98.9% and fatty acids methyl esters yields of 94.6%. The activity results also confirmed the high activity of the carrier material (NZ) itself in the investigated reaction. Support material exhibited 90.5% of TG conversion and the Fatty Acid Methyl Esters yield (FAME) of 67.2%. Introduction of noble metals improves the TG conversion and FAME yield values. Increasing of the metal loading from 0.5 to 2 wt.% improves the reactivity properties of the investigated catalysts.


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