Fabrication of single phase CsPbBr3 films via in situ metal reaction

CrystEngComm ◽  
2021 ◽  
Vol 23 (16) ◽  
pp. 2938-2944
Author(s):  
Lijia Guo ◽  
Manying Liu ◽  
Yan Lei ◽  
Liwei Mi ◽  
Zhi Zheng
Keyword(s):  
Single Phase

We developed an in situ metal reaction strategy to fabricate single phase CsPbBr3 films by reacting Pb precursors with a mixture of CsBr and HBr. The purity of the CsPbBr3 film can be controlled by tuning the thickness of sputtered Pb.

SYNTHESIS, STRUCTURAL, OPTICAL AND ELECTRICAL PROPERTIES OF IN-SITU SYNTHESIZED POLYANILINE/SILVER NANOCOMPOSITES

2012 ◽  
Vol 05 (03) ◽  
pp. 1250026 ◽  
Author(s):  
FAHAD ALAM ◽  
SAJID ALI ANSARI ◽  
WASI KHAN ◽  
M. EHTISHAM KHAN ◽  
A. H. NAQVI
Keyword(s):  
Single Phase ◽  
In Situ Polymerization ◽  
Optical And Electrical Properties ◽  
Silver Colloid ◽  
Dielectric Measurements ◽  
Temperature Dependent ◽  
Colloidal Form ◽  
Uv Visible ◽  
Temperature Dependent Resistivity

Polyaniline (PANI) is recognized as one of the most important conducting polymers due to its high conductivity and good stability. In this paper, polyaniline/silver (PANI/Ag) nanocomposites were synthesized by in-situ polymerization of aniline using ammonium peroxydisulphate (APS) as oxidizing agent with varying concentration of Ag nanoparticles colloids (0 ml, 25 ml and 50 ml). Silver nanoparticles were synthesized separately in colloidal form from silver nitrate (Ag2NO3) with the help of reducing agent sodium borohydride (NaBH4). The PANI/ Ag nanocomposites were characterized by XRD, SEM, AFM, UV-visible, temperature dependent resistivity and dielectric measurements. All samples show a single phase nature of the nanoparticles. The electrical resistivity as function of temperature was measured in the temperature range 298–383 K, which indicates a semiconducting to metallic transition at 373 K and 368 K for 25 ml and 50 ml silver colloid samples, respectively.

scholarly journals Synthesis and Novel Purification Process of PANI and PANI/AgNPs Composite

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1621 ◽  
Author(s):  
María L. Mota ◽  
Amanda Carrillo ◽  
Ana J. Verdugo ◽  
Amelia Olivas ◽  
Jorge M. Guerrero ◽  
...  
Keyword(s):  
Single Phase ◽  
Oxidative Polymerization ◽  
Purification Process ◽  
Separation System ◽  
Purification Technique ◽  
Percentage Yield ◽  
Temperature Time ◽  
Pani Matrix ◽  
Time Of Reaction

In this work, polyaniline (PANI) is synthesized via oxidative polymerization of aniline and purified using organic solvents where the emeraldine phase is isolated by employing a phase separation system. The above contributes to the increase in the percentage yield compared to previous works and the possibility of being used as a single phase. In addition, the PANI/AgNPs composite is prepared in situ at the polymerization of aniline, adding silver nitrate and glycine to create the AgNPs inside the PANI matrix by controlling the pH, temperature, time of reaction and incorporating a new purification technique.

scholarly journals One-step ultra-rapid fabrication and thermoelectric properties of Cu2Se bulk thermoelectric material

RSC Advances ◽  
2019 ◽  
Vol 9 (19) ◽  
pp. 10508-10519 ◽  
Author(s):  
Tiezheng Hu ◽  
Yonggao Yan ◽  
Si Wang ◽  
Xianli Su ◽  
Wei Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Thermoelectric Properties ◽  
Single Phase ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Thermoelectric Energy ◽  
Rapid Fabrication ◽  
One Step ◽  
First Time

Cu2Se is a promising material for thermoelectric energy conversion. Fully dense single-phase bulk Cu2Se was prepared by the combination of self-propagating high-temperature synthesis with in situ quick pressing for the first time.

Na2.3Cu1.1Mn2O7−δ nanoflakes as enhanced cathode materials for high-energy sodium-ion batteries achieved by a rapid pyrosynthesis approach

2020 ◽  
Vol 8 (2) ◽  
pp. 770-778 ◽  
Author(s):  
Vaiyapuri Soundharrajan ◽  
Balaji Sambandam ◽  
Muhammad H. Alfaruqi ◽  
Sungjin Kim ◽  
Jeonggeun Jo ◽  
...  
Keyword(s):  
Cathode Materials ◽  
Single Phase ◽  
High Energy ◽  
Positive Electrode ◽  
Sodium Ion ◽  
Sodium Ion Batteries ◽  
Phase Reaction

Na2.3Cu1.1Mn2O7−δ nanoflakes prepared by an ultrafast pyrosynthesis approach are used as the positive electrode for SIBs. In situ GITT and XRD results support the occurrence of a single-phase reaction in the Na2.3Cu1.1Mn2O7−δ nanoflakes cathode during Na+ (de)intercalation.

scholarly journals Compositional simulation of hydrocarbon recovery from oil shale reservoirs with diverse initial saturations of fluid phases by various thermal processes

2016 ◽  
Vol 35 (2) ◽  
pp. 172-193 ◽  
Author(s):  
Kyung Jae Lee ◽  
George J Moridis ◽  
Christine A Ehlig-Economides
Keyword(s):  
Aqueous Phase ◽  
Single Phase ◽  
Water Injection ◽  
Hot Water ◽  
Electrical Heating ◽  
Hydrocarbon Production ◽  
Well Pattern ◽  
Shale Reservoirs ◽  
Fluid Phases

We have studied the hydrocarbon production from oil shale reservoirs filled with diverse initial saturations of fluid phases by implementing numerical simulations of various thermal in-situ upgrading processes. We use our in-house fully functional, fully implicit, and non-isothermal simulator, which describes the in-situ upgrading processes and hydrocarbon recovery by multiphase-multicomponent systems. We have conducted two sets of simulation cases—five-spot well pattern problems and Shell In-situ Conversion Process (ICP) problems. In the five-spot well pattern problems, we have analyzed the effects of initial fluid phase that fills the single-phase reservoir and thermal processes by four cases—electrical heating in the single-phase-aqueous reservoir, electrical heating in the single-phase-gaseous reservoir, hot water injection in the single-phase-aqueous reservoir, and hot CO2 injection in the single-phase-gaseous reservoir. In the ICP problems, we have analyzed the effects of initial saturations of fluid phases that fill two-phase-aqueous-and-gaseous reservoir by three cases—initial aqueous phase saturations of 0.16, 0.44, and 0.72. Through the simulation cases, system response and production behavior including temperature profile, kerogen fraction profile, evolution of effective porosity and absolute permeability, phase production, and product selectivity are analyzed. In the five-spot well pattern problems, it is found that the hot water injection in the aqueous phase reservoir shows the highest total hydrocarbon production, but also shows the highest water-oil-mass-ratio. Productions of phases and components show very different behavior in the cases of electrical heating in the aqueous phase reservoir and the gaseous phase reservoir. In the ICP problems, it is found that the speed of kerogen decomposition is almost identical in the cases, but the production behavior of phases and components is very different. It is found that more liquid organic phase has been produced in the case with the higher initial saturation of aqueous phase by the less production of gaseous phase.

Formation of in-situ reinforced microstructure in α–sialon ceramics I: Stoichiometric oxygen-rich compositions

2002 ◽  
Vol 17 (2) ◽  
pp. 336-342 ◽  
Author(s):  
Zhijian Shen ◽  
Hong Peng ◽  
Mats Nygren
Keyword(s):  
Hot Pressing ◽  
Single Phase ◽  
Transient Liquid Phase ◽  
Precursor Powder ◽  
Temperature Dependent ◽  
Consolidation Process ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Equiaxed Grains

The abnormal grain growth in α–sialon ceramics was investigated. The preparations had stoichiometric compositions on the oxygen-rich phase boundary, and they were stabilized by Y, Nd, Sm, Dy, and Yb, respectively. Specimens were prepared from α–Si3N4 as precursor powder by applying conventional hot pressing and a novel rapid consolidation process, namely spark plasma sintering (SPS). Single-phase α–sialon ceramics with in situ reinforced bimodal microstructure, i.e., large elongated grains embedded in a matrix consisting of small equiaxed grains, were obtained above 1750 °C in all systems compacted by SPS and above 1800 °C in systems stabilized by Nd and Sm but not Dy, Y, or Yb by a two-step hot-pressing procedure. It was observed that the formation of abnormally grown α–sialon grains was strongly temperature-dependent, indicating that it was encouraged by the formation of a transient liquid phase that stimulated the dissolution of any remaining nitride precursors and early formed small α–sialon grains and sequentially facilitated supersaturation by the α–sialon constituents. The presence of elongated grains improves fracture resistance in the obtained materials.

Direct Preparation of Ce0.8Sm0.2O1.9 Powders Oxidized With H2O2 for Low Temperature SOFCs Application

2005 ◽  
Author(s):  
Jianbing Huang ◽  
Zongqiang Mao ◽  
Bin Zhu ◽  
Lizhai Yang ◽  
Ranran Peng ◽  
...  
Keyword(s):  
Single Phase ◽  
Fluorite Structure ◽  
X Ray Diffraction ◽  
Composite Electrolyte ◽  
Xrd Pattern ◽  
Transmission Electron ◽  
Direct Preparation ◽  
Novel Method ◽  
Power Densities

A novel method was developed to prepare fine doped ceria (DCO) powders directly. Ceria doped with 20 mol. % of samarium (Ce0.8Sm0.2O1.9, SDC) was prepared by in-situ oxidization of hydroxide precipitates with H2O2 in the solutions. The resultant powder desiccated at 85°C overnight was characterized by X-ray diffraction (XRD), thermogravimetry /differential thermal analysis (TG/DTA), and transmission electron microscopy (TEM). The XRD pattern showed that the as-dried SDC powder is single phase with a cubic fluorite structure like that of pure CeO2. An anode-supported SOFC was also fabricated based on SDC and 20wt. % (62mol. %Li2CO3–38 mol. %K2CO3) composite electrolyte, LiNiO2 as cathode and NiO as anode, by cold pressing. Using hydrogen as the fuel and air as the oxidant, the I-V and I-P characteristics exhibit excellent performances and the maximum power densities are about 696, 469, 377 and 240 mWcm−2 at 650, 600, 550 and 500°C, respectively.

scholarly journals Rheology-based method for calculating polymer inaccessible pore volume in core flooding experiments

2019 ◽  
Vol 89 ◽  
pp. 04001 ◽  
Author(s):  
V. H. S. Ferreira ◽  
R. B. Z. L. Moreno
Keyword(s):  
Shear Rate ◽  
Pore Volume ◽  
Single Phase ◽  
Relative Difference ◽  
Core Flooding ◽  
Two Phase ◽  
Shear Rates ◽  
The Core ◽  
Inaccessible Pore Volume

Polymer flooding is an enhanced oil recovery (EOR) method that reduces the mobility ratio between the displaced oil and the displacing injected water. The flow of polymer solutions through porous media is subject to some process-specific phenomena, such as the inaccessible pore volume (IAPV). Due to IAPV, polymer molecules move faster through the porous medium than smaller ones. Thus the IAPV value needs to be accounted for in experiments and field projects. Recent reports found that polymer in-situ rheology correlates with the IAPV. The objective of this paper is to develop a method for estimating IAPV based on the in-situ rheology of polymers. The methodology proposed here can be used in both single- and two-phase experiments. The technique requires measurement of polymer resistance factor (RF) and residual resistance factor (RRF) at steady state conditions. Core permeability, porosity, and residual oil saturation, as well as water and polymer bulk viscosities, also need to be taken into account. Correlations for polymer in-situ viscosity and shear rate are solved simultaneously, to wield an estimative for the IAPV. Aiming at to prove the method, we report 16 core-flooding experiments, eight single- and eight two-phase experiments. We used a flexible polymer and sandstone cores. All the tests were run using similar rock samples. In the single-phase experiments, we compare the alternative method with the classic tracer method to estimate IAPV. The results show an average relative difference of 11.5% between the methods. The two-phase results display, on average, an 18% relative difference to the IAPV measured in the single-phase experiments. The difference between single- and two-phase results can be an effect of the higher shear rates experienced in the two-phase floodings since, in these cases, the aqueous phase shear rate is also dependent on the phase saturation. Additionally, temperature, core length, pore pressure, and iron presence on the core did not show any influence on the IAPV for our two-phase experiments. The method proposed in this paper is limited by the accuracy of the pressure drop measurements across the core. For flexible polymers, the method is valid only for low and mid shear rates, but, accoording to literature, for rigid polymers the method should be accurate for a broad range of shear rates. The method proposed here allows the measurement of polymer IAPV on two- and single- phase core-flooding experiments when a tracer is not used.

scholarly journals In-Situ Imaging of Molten High-Entropy Alloys Using Cold Neutrons

2019 ◽  
Vol 5 (2) ◽  
pp. 29 ◽  
Author(s):  
Nicholas Derimow ◽  
Louis Santodonato ◽  
Benjamin MacDonald ◽  
Bryan Le ◽  
Enrique Lavernia ◽  
...  
Keyword(s):  
Real Time ◽  
Liquid State ◽  
Single Phase ◽  
Neutron Imaging ◽  
Phase Changes ◽  
Vacuum Furnace ◽  
In Situ Observation ◽  
Complex Alloy ◽  
Phase Liquid

Real-time neutron imaging was utilized to produce a movie-like series of radiographs for in-situ observation of the remixing of liquid state immiscibility that occurs in equiatomic CoCrCu with the addition of Ni. A previous neutron imaging study demonstrated that liquid state immiscibility can be observed in-situ for the equiatomic CoCrCu alloy. In this follow-up study, equiatomic buttons of CoCrCu were placed alongside small Ni buttons inside an alumina crucible in a high-temperature vacuum furnace. The mass of the Ni buttons was specifically selected such that when melted in the same crucible as the CoCrCu buttons, the overall composition would become equiatomic CoCrCuNi. Neutron imaging was simultaneously carried out to capture 10 radiographs in 20 °C steps from 1000 °C to 1500 °C and back down to 1000 °C. This, in turn, produced a movie-like series of radiographs that allow for the observation of the buttons melting, the transition from immiscible to miscible as Ni is alloyed into the CoCrCu system, and solidification. This novel imaging process showed the phase-separated liquids remixing into a single-phase liquid when Ni dissolves into the melt, which makes this technique crucial for understanding the liquid state behavior of these complex alloy systems. As metals are not transparent to X-ray imaging techniques at this scale, neutron imaging of melting and solidification allows for the observation of liquid state phase changes in real time. Thermodynamic calculations of the isopleth for CoCrCuNix were carried out to compare the observed results to the predictions resulting from the current Thermo-Calc TCHEA3 thermodynamic database. The calculations show a very good agreement with the experimental results, as the calculations indicate that the CoCrCuNix alloy solidifies from a single-phase liquid when x ≥ 0.275, which is close to the nominal concentration of the CoCrCuNi alloy (x = 0.25). The neutron imaging shows that the solidification of CoCrCuNi results from a single-phase liquid. This is evident as no changes in the neutron attenuation were observed during the solidification of the CoCrCuNi alloy.

Partial Pressure Differential and Rapid Thermal Annealing for Integrated Yttrium Iron Garnet (Yig)

2004 ◽  
Vol 817 ◽  
Author(s):  
Sang-Yeob Sung ◽  
Xiaoyaun Qi ◽  
Samir K. Mondal ◽  
Bethanie J. H Stadler
Keyword(s):  
Single Phase ◽  
Rf Sputtering ◽  
Buffer Layers ◽  
X Ray Diffraction ◽  
Wide Range ◽  
Out Of Plane ◽  
In Situ Crystallization ◽  
Iron Garnet ◽  
Single Phase Field

In this work, magneto-optical garnets were grown monolithically by low-temperature reactive RF sputtering, followed by an ultra-short (< 15sec) anneal. It was found that in addition to low thermal budgets due to timing, the temperature required (< 750°C) for garnet crystallization was also reduced compared to standard tube furnace annealing (> 1000°C). MgO and fused quartz were used as substrates because they will be useful for future buffer layers and optical claddings. Y-Fe-O films were made with systematically varied compositions and the chemical, structural, and optical properties of the resulting films were analyzed. A solid solution single phase field for YIG was found that spanned a wide range of compositions (30.1 ∼ 49.0 atomic % of Fe). The resulting YIG quality was measured by vibrating sample magnetometry (VSM), X-ray diffraction (XRD), and measurements of Faraday rotation (FR). Although the XRD results showed that the films had isotropic crystallinity, the VSM indicated that shape anisotropy dominated the magnetic properties. Out of plane FR measurements yielded up to 0.2°/μm at 632nm rotations. This rotation will be higher in plane. All of these tests demonstrated that the YIG was comparable to YIG grown by standard annealing and also by in-situ crystallization.

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