scholarly journals Chemistry and Technology of Samarium Monosulfide

2016 ◽  
Vol 18 (1) ◽  
pp. 55 ◽  
Author(s):  
O.V. Andreev ◽  
V.V. Ivanov ◽  
A.V. Gorshkov ◽  
P.V. Miodushevskiy ◽  
P.O. Andreev
Keyword(s):  
Heat Treatment ◽  
Large Scale ◽  
Film Deposition ◽  
Congruent Melting ◽  
Flash Evaporation ◽  
Sensitive Material ◽  
X Ray ◽  
Pressure Sensitive ◽  
Congruent Melting Temperature ◽  
Samarium Monosulfide

<p class="Pa10">Samarium monosulfide SmS (Fm3m, а = 5.967 Å, ΔЕ = 0.23 V, n = 10<sup>20</sup> cm<sup>–1</sup>, <em>σ</em><em> </em>= 500 Ω<sup>–1</sup> cm<sup>–1</sup>, <em>α</em><em> </em>= 350 μВ/K) is a thermoelectric material (Z&gt;1) and, at the same time, a pressure-sensitive material (K≥40–50). Samarium monosulfide is a daltonide phase with a solid solution whose extent is mostly in the range of cationic vacancies: Sm<sub>1+x </sub>S<sub>1-x</sub>□<sub>2x</sub> (<em>x </em>= 0–0.035; 1750 K). The congruent melting temperature of SmS is 2475 K. In the Sm–S system, Sm<sub>3</sub>S<sub>4</sub> crystallizes from melt without change in composition. Samarium monosulfide thermally dissociates to Sm<sub>3</sub>S<sub>4</sub> and Sm. Large-scale SmS lots are produced from samarium and sulfur. Synthesis is carried out in sealed-off silica glass ampoules at 500–1350 K followed by heat treatment in tantalum crucibles at 1500–2400 K. The reaction of metal samarium with sulfur results in the formation of sulfide phases that coat the samarium surface in the following order: SmS, Sm<sub>3</sub>S<sub>4</sub>, Sm<sub>2</sub>S<sub>3</sub>, and SmS<sub>2</sub>. Subsequent annealing at 1500–1800 K provides SmS yields up to 96–97 mol %. Equilibrium minor phases for SmS are Sm<sub>3</sub>S<sub>4</sub>, Sm<sub>2</sub>О<sub>2</sub>S, and Sm. X-ray amorphous SmS was prepared by reacting organic samarium compounds with sulfur or H2S. The samarium (+2) oxidation state determines the chemical specifics of SmS. 90–120 μm SmS powders are thermally hydrolyzed starting at 600 K with Н<sub>2</sub> evolution and oxidize starting at 520 K to yield Sm<sub>3</sub>S<sub>4</sub> and then Sm<sub>2</sub>О<sub>2</sub>S phases. A 90–120 μm SmS fraction for film deposition by flash evaporation is prepared by milling annealed SmS samples. Tablets 75 mm in diameter for use in magnetron sputtering are pressed from a &lt;60-μm fraction.</p>

Macro-Observation of the Interface of the Al-22%Si-Cu/Al-7%Si-MG Bi-Metal Parts Fabricated by Thixoforging

2016 ◽  
Vol 256 ◽  
pp. 69-74
Author(s):  
Zhao Yang ◽  
Guang Xu Wang ◽  
Xue Xuan Xu ◽  
Xiao Long He ◽  
Jian Ning Lu
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Large Scale ◽  
Optical Microscope ◽  
Flaw Detector ◽  
X Ray ◽  
Volume Stability ◽  
Metal Parts ◽  
T6 Heat Treatment ◽  
Average Tensile Strength

Thixo-forging has been proved to be able to fabricate bi-metal parts with a complex outline and a relatively regular interface economically. These products have potential applications on high volume stability radiators, brakes, and pistons. However, it is very difficult to evaluate the curved interfaces by micro observations. In this work, Al-22%Si-Cu/Al-7%Si-Mg bi-metal parts were fabricated by thixo-forging; state of the interfaces of the bi-metal parts was investigated by X-ray flaw detector observations and tensile test; optical microscope (OM) observation and scan electron microscope (SEM) observation were applied to assist the analysis. The results show that the metallurgical bonding of the interfaces is of good quality. No large scale flaw was found on the interface in X-ray flaw detector observation. It was found that higher forging pressure decreased the size of the crack on the interface and in the matrix. However, higher forging pressure can slightly improve tensile strength. Large ratio of fresh interface relates to original interface resulted in a slightly better tensile strength. Without heat-treatment, the bi-metal forgings have an average tensile strength of 106 MPa. T6 heat treatment blunted the blades of the plate like crack and nodulized the defects, T6 heat treatment also decreased the size of the Si particles. As a result, the average tensile strength of the bi-metal forgings increased to 200 MPa.

scholarly journals Controllable deposition of organic metal halide perovskite films with wafer-scale uniformity by single source flash evaporation

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Woocheol Lee ◽  
Jonghoon Lee ◽  
Hyeon-Dong Lee ◽  
Junwoo Kim ◽  
Heebeom Ahn ◽  
...  
Keyword(s):  
Large Scale ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Scale Production ◽  
Single Source ◽  
Flash Evaporation ◽  
Large Area ◽  
Lead Iodide ◽  
Wafer Scale ◽  
Evaporation Technique

Abstract Conventional solution-processing techniques such as the spin-coating method have been used successfully to reveal excellent properties of organic–inorganic halide perovskites (OHPs) for optoelectronic devices such as solar cell and light-emitting diode, but it is essential to explore other deposition techniques compatible with large-scale production. Single-source flash evaporation technique, in which a single source of materials of interest is rapidly heated to be deposited in a few seconds, is one of the candidate techniques for large-scale thin film deposition of OHPs. In this work, we investigated the reliability and controllability of the single-source flash evaporation technique for methylammonium lead iodide (MAPbI3) perovskite. In-depth statistical analysis was employed to demonstrate that the MAPbI3 films prepared via the flash evaporation have an ultrasmooth surface and uniform thickness throughout the 4-inch wafer scale. We also show that the thickness and grain size of the MAPbI3 film can be controlled by adjusting the amount of the source and number of deposition steps. Finally, the excellent large-area uniformity of the physical properties of the deposited thin films can be transferred to the uniformity in the device performance of MAPbI3 photodetectors prepared by flash evaporation which exhibited the responsivity of 0.2 A/W and detectivity of 3.82 × 1011 Jones.

scholarly journals Biopolymer Composites with Ti/Au Nanostructures and Their Antibacterial Properties

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 826
Author(s):  
Petr Slepička ◽  
Dominik Fajstavr ◽  
Markéta Krejčová ◽  
Silvie Rimpelová ◽  
Nikola Slepičková Kasálková ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Large Scale ◽  
Antibacterial Properties ◽  
Chemical Properties ◽  
Laser Confocal Microscopy ◽  
Cathode Sputtering ◽  
X Ray ◽  
E Coli ◽  
Atomic Force

In this study, we have aimed at the preparation and characterization of poly-l-lactic acid (PLLA) composites with antibacterial properties. Thin bilayers of titanium and gold of various thickness ratios were deposited on PLLA by a cathode sputtering method; selected samples were subsequently thermally treated. The surface morphology of the prepared composites was studied by atomic force, scanning electron, and laser confocal microscopy. The chemical properties of the composites were determined by X-ray photoelectron and energy-dispersive X-ray spectroscopy in combination with contact angle and zeta potential analyses. The antibacterial properties of selected samples were examined against a Gram-negative bacterial strain of E. coli. We have found that a certain combination of Au and Ti nanolayers in combination with heat treatment leads to the formation of a unique wrinkled pattern. Moreover, we have developed a simple technique by which a large-scale sample modification can be easily produced. The dimensions of wrinkles can be tailored by the sequence and thickness of the deposited metals. A selected combination of gold, titanium, and heat treatment led to the formation of a nanowrinkled pattern with excellent antibacterial properties.

scholarly journals Large-Area Sodium Titanate Nanorods Formed On Titanium Surface Via NaOH Alkali Treatment

2015 ◽  
Vol 60 (2) ◽  
pp. 1371-1374 ◽  
Author(s):  
K. Lee ◽  
D. Yoo
Keyword(s):  
Heat Treatment ◽  
Energy Conversion ◽  
Large Scale ◽  
Titanium Surface ◽  
Alkali Treatment ◽  
Sodium Titanate ◽  
Morphological Characterization ◽  
X Ray Diffraction ◽  
Large Area ◽  
X Ray

AbstractTi surfaces covered with large sodium titanate nanorods act as efficient electrodes for energy conversion and environmental applications. In this study, sodium titanate nanorod films were prepared on a Ti substrate in a 5M NaOH aqueous solution followed by heat treatment. The morphological characterization and the crystal structures of the sodium titanate nanorods were investigated via scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive spectroscopy (EDS). Thin amorphous sodium titanate layers formed during the alkali-treatment, and sodium titanate nanorods were obtained after heat treatment at a temperature of 700°C. The sodium titanate nanorods obtained at this temperature had a thickness of about 80 nm and a length of 1μm. The crystal structure of the sodium titanate was identified with the use of Na2Ti5O11. The nanorods were agglomerated at a temperature above 900°C, and large-scale nanorods formed on the Ti surface, which may be used for electrodes for energy conversion applications.

TEM studies of pulse electrodeposited Cu-Se and CuInSe2 films

1990 ◽  
Vol 48 (4) ◽  
pp. 696-697
Author(s):  
G. Veilleux ◽  
M. Boumerzoug ◽  
R.G. Saint-Jacques ◽  
Lê H. Dao
Keyword(s):  
Thin Film ◽  
Heat Treatment ◽  
Indium Tin Oxide ◽  
Large Scale ◽  
Low Cost ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Phase Changes ◽  
Solution Ph ◽  
Ito Glass

Photovoltaic technology is considered as one of the major options for large-scale energy production without pollution. Thin-film technologies are seen as a potential approach to produce cost-effective electricity by photovoltaic. Among the different thin-film deposition techniques (CVD, vacuum evaporation, sputtering, etc.), electrodeposition has emerged as a low-cost method. Using a pulsed electrodeposition technique semiconductor thin films of Cu-Se and CuInSe2 with improved uniformity and lower impurity have been prepared. Varying the electrodeposition solution pH, stoichiometric CuSe, Cu3Se2, Cu2 Se and Cu2Se films on Indium Tin Oxide (ITO) coated glass or Ni electrodes were obtained. Their composition and properties varied with heat treatment (3).This paper reports the detailed study by Energy-Dispersive Spectrometry (EDS) and Transmission Electron Microscopy (TEM) of heat treatment effects on the composition and phase changes. EDS analyses were done on films deposited onto ITO glass using an Hitachi S-530 Scanning Electron Microscope (SEM). Cerac 99.99% pure powders were used to establish EDS calibration spectra. TEM studies were done on films directly deposited onto Ni grids. Selected area diffraction pattern (SADP) analyses were used to identify the structures. Samples were examined in a Philips EM-300 TEM operated at 100 kV.

The Precipitation of Si in AlCuSi Thin Films

1973 ◽  
Vol 31 ◽  
pp. 34-35 ◽  
Author(s):  
R. M. Anderson
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Heat Treatment ◽  
Solid Solution ◽  
Integrated Circuit ◽  
Copper Film ◽  
Solution Concentration ◽  
X Ray ◽  
Silicon Thin Films ◽  
Before And After

Aluminum-copper-silicon thin films have been considered as an interconnection metallurgy for integrated circuit applications. Various schemes have been proposed to incorporate small percent-ages of silicon into films that typically contain two to five percent copper. We undertook a study of the total effect of silicon on the aluminum copper film as revealed by transmission electron microscopy, scanning electron microscopy, x-ray diffraction and ion microprobe techniques as a function of the various deposition methods.X-ray investigations noted a change in solid solution concentration as a function of Si content before and after heat-treatment. The amount of solid solution in the Al increased with heat-treatment for films with ≥2% silicon and decreased for films <2% silicon.

Layered and ion implantation specimens as possible reference materials for the electron-probe microanalysis

1992 ◽  
Vol 50 (2) ◽  
pp. 1652-1653
Author(s):  
G. Remond ◽  
R.H. Packwood ◽  
C. Gilles ◽  
S. Chryssoulis
Keyword(s):  
Ion Implantation ◽  
Reference Materials ◽  
Analytical Techniques ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
X Ray ◽  
Spatially Resolved ◽  
Analytical Expressions ◽  
Original Approach ◽  
Depth Concentration

Merits and limitations of layered and ion implanted specimens as possible reference materials to calibrate spatially resolved analytical techniques are discussed and illustrated for the case of gold analysis in minerals by means of x-ray spectrometry with the EPMA. To overcome the random heterogeneities of minerals, thin film deposition and ion implantation may offer an original approach to the manufacture of controlled concentration/ distribution reference materials for quantification of trace elements with the same matrix as the unknown.In order to evaluate the accuracy of data obtained by EPMA we have compared measured and calculated x-ray intensities for homogeneous and heterogeneous specimens. Au Lα and Au Mα x-ray intensities were recorded at various electron beam energies, and hence at various sampling depths, for gold coated and gold implanted specimens. X-ray intensity calculations are based on the use of analytical expressions for both the depth ionization Φ (ρz) and the depth concentration C (ρz) distributions respectively.

scholarly journals X-ray Determination of Compressive Residual Stresses in Spring Steel Generated by High-Speed Water Quenching

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1154
Author(s):  
Diego E. Lozano ◽  
George E. Totten ◽  
Yaneth Bedolla-Gil ◽  
Martha Guerrero-Mata ◽  
Marcel Carpio ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Residual Stresses ◽  
High Speed ◽  
Spring Steel ◽  
X Ray Diffraction ◽  
Laboratory Equipment ◽  
X Ray ◽  
Water Chamber ◽  
Hardened Case ◽  
Compressive Residual Stresses

Automotive components manufacturers use the 5160 steel in leaf and coil springs. The industrial heat treatment process consists in austenitizing followed by the oil quenching and tempering process. Typically, compressive residual stresses are induced by shot peening on the surface of automotive springs to bestow compressive residual stresses that improve the fatigue resistance and increase the service life of the parts after heat treatment. In this work, a high-speed quenching was used to achieve compressive residual stresses on the surface of AISI/SAE 5160 steel samples by producing high thermal gradients and interrupting the cooling in order to generate a case-core microstructure. A special laboratory equipment was designed and built, which uses water as the quenching media in a high-speed water chamber. The severity of the cooling was characterized with embedded thermocouples to obtain the cooling curves at different depths from the surface. Samples were cooled for various times to produce different hardened case depths. The microstructure of specimens was observed with a scanning electron microscope (SEM). X-ray diffraction (XRD) was used to estimate the magnitude of residual stresses on the surface of the specimens. Compressive residual stresses at the surface and sub-surface of about −700 MPa were obtained.

scholarly journals On the relation between mini-halos and AGN feedback in clusters of galaxies

2020 ◽  
Vol 499 (2) ◽  
pp. 2934-2958
Author(s):  
A Richard-Laferrière ◽  
J Hlavacek-Larrondo ◽  
R S Nemmen ◽  
C L Rhea ◽  
G B Taylor ◽  
...  
Keyword(s):  
Large Scale ◽  
State Of The Art ◽  
Vital Role ◽  
Clusters Of Galaxies ◽  
Relativistic Jets ◽  
X Ray ◽  
Core Cluster ◽  
Central Galaxy ◽  
Central Regions ◽  
Radio Power

ABSTRACT A variety of large-scale diffuse radio structures have been identified in many clusters with the advent of new state-of-the-art facilities in radio astronomy. Among these diffuse radio structures, radio mini-halos are found in the central regions of cool core clusters. Their origin is still unknown and they are challenging to discover; less than 30 have been published to date. Based on new VLA observations, we confirmed the mini-halo in the massive strong cool core cluster PKS 0745−191 (z = 0.1028) and discovered one in the massive cool core cluster MACS J1447.4+0827 (z = 0.3755). Furthermore, using a detailed analysis of all known mini-halos, we explore the relation between mini-halos and active galactic nucleus (AGN) feedback processes from the central galaxy. We find evidence of strong, previously unknown correlations between mini-halo radio power and X-ray cavity power, and between mini-halo and the central galaxy radio power related to the relativistic jets when spectrally decomposing the AGN radio emission into a component for past outbursts and one for ongoing accretion. Overall, our study indicates that mini-halos are directly connected to the central AGN in clusters, following previous suppositions. We hypothesize that AGN feedback may be one of the dominant mechanisms giving rise to mini-halos by injecting energy into the intra-cluster medium and reaccelerating an old population of particles, while sloshing motion may drive the overall shape of mini-halos inside cold fronts. AGN feedback may therefore not only play a vital role in offsetting cooling in cool core clusters, but may also play a fundamental role in re-energizing non-thermal particles in clusters.

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