scholarly journals Dominating the Structural, Microstructural and Magnetic Features of Li+ Substituted Strontium Hexaferrite (Sr1-xLi2xFe12O19)

2021 ◽  
Author(s):  
Mahmoud Hessien ◽  
Nader El-Bagoury ◽  
M. H. H. Mahmoud ◽  
M. Alsawat ◽  
Abdullah ALanazi ◽  
...  
Keyword(s):  
Annealing Temperature ◽  
Lithium Ion ◽  
Spherical Shape ◽  
Phase Evolution ◽  
Hexagonal Ferrite ◽  
Strontium Hexaferrite ◽  
X Ray Diffraction ◽  
Diffraction Profile ◽  
The Impact ◽  
Platelet Shape

Abstract Lithium ion substituted hexagonal strontium ferrite (Sr1-xLi2xFe12O19, where x= 0.1, 0.2, and 0.3) powders have been felicitously fabricated using tartrate precursor scheme. The impact of the Li+ content, as well as the annealing temperature on the phase evolution, microstructure and magnetic performance, was commanded by X-ray diffraction profile (XRD), scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM). Single phase hexagonal ferrite was consummated at a Li+ ratio of 0.2 and different annealing temperatures, from 1000 to 1200oC for 2h. An impurity α-Fe2O3 phase was noted at a high Li+ concentration of 0.4 and 0.6 at all temperatures. The crystallo-aspects characteristics were altered with Li+ content and annealing temperature. The microstructure of pure hexagonal ferrite sample visualized platelet like structure. A fine spherical shape displayed with platelet shape by enhancing the Li+ content up to 0.4 and 0.6. EDX analysis emphasized Fe, Sr, O, and Li atoms spread between the plate and spherical shapes. Good saturation magnetization (Ms=60.88 emu/g) was realized for Li+ content of 0.2 as the results of increasing the thickness of the nanoplatelet structure.

scholarly journals A Study of Thin Film Resistors Prepared Using Ni-Cr-Si-Al-Ta High Entropy Alloy

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Ruei-Cheng Lin ◽  
Tai-Kuang Lee ◽  
Der-Ho Wu ◽  
Ying-Chieh Lee
Keyword(s):  
Annealing Temperature ◽  
Phase Evolution ◽  
Amorphous Structure ◽  
High Entropy Alloy ◽  
X Ray Diffraction ◽  
Temperature Coefficient Of Resistance ◽  
X Ray ◽  
High Entropy ◽  
Transmission Electron ◽  
Thin Film Resistors

Ni-Cr-Si-Al-Ta resistive thin films were prepared on glass and Al2O3substrates by DC magnetron cosputtering from targets of Ni0.35-Cr0.25-Si0.2-Al0.2casting alloy and Ta metal. Electrical properties and microstructures of Ni-Cr-Si-Al-Ta films under different sputtering powers and annealing temperatures were investigated. The phase evolution, microstructure, and composition of Ni-Cr-Si-Al-Ta films were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and Auger electron spectroscopy (AES). When the annealing temperature was set to 300°C, the Ni-Cr-Si-Al-Ta films with an amorphous structure were observed. When the annealing temperature was at 500°C, the Ni-Cr-Si-Al-Ta films crystallized into Al0.9Ni4.22, Cr2Ta, and Ta5Si3phases. The Ni-Cr-Si-Al-Ta films deposited at 100 W and annealed at 300°C which exhibited the higher resistivity 2215 μΩ-cm with −10 ppm/°C of temperature coefficient of resistance (TCR).

scholarly journals A Study on the Characteristics of Cu–Mn–Dy Alloy Resistive Thin Films

Coatings ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 118 ◽  
Author(s):  
Ho-Yun Lee ◽  
Chi-Wei He ◽  
Ying-Chieh Lee ◽  
Da-Chuan Wu
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Annealing Temperature ◽  
Phase Evolution ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
Temperature Coefficient Of Resistance ◽  
X Ray ◽  
Transmission Electronmicroscopy ◽  
Scanning Electron

Cu–Mn–Dy resistive thin films were prepared on glass and Al2O3 substrates, which wasachieved by co-sputtering the Cu–Mn alloy and dysprosium targets. The effects of the addition ofdysprosium on the electrical properties and microstructures of annealed Cu–Mn alloy films wereinvestigated. The composition, microstructural and phase evolution of Cu–Mn–Dy films werecharacterized using field emission scanning electron microscopy, transmission electronmicroscopy and X-ray diffraction. All Cu–Mn–Dy films showed an amorphous structure when theannealing temperature was set at 300 °C. After the annealing temperature was increased to 350 °C,the MnO and Cu phases had a significant presence in the Cu–Mn films. However, no MnO phaseswere observed in Cu–Mn–Dy films at 350 °C. Even Cu–Mn–Dy films annealed at 450 °C showedno MnO phases. This is because Dy addition can suppress MnO formation. Cu–Mn alloy filmswith 40% dysprosium addition that were annealed at 300 °C exhibited a higher resistivity of ∼2100 μΩ·cm with a temperature coefficient of resistance of –85 ppm/°C.

Electrochemical Performance of Sol-Gel Derived Hexagonal LiMnBO3 Cathode Material for Lithium-Ion Batteries

2017 ◽  
Vol 17 ◽  
pp. 106-112 ◽  
Author(s):  
Veena Ragupathi ◽  
K. Srimathi ◽  
P. Panigrahi ◽  
J.W. Lee ◽  
Ganapathi Subramanian Nagarajan
Keyword(s):  
Thermal Analysis ◽  
Raman Spectroscopy ◽  
Sol Gel ◽  
Lithium Ion ◽  
Spherical Shape ◽  
Average Diameter ◽  
Electrochemical Characteristics ◽  
X Ray Diffraction ◽  
Sem Image ◽  
Group Stability

An attempt has been made to synthesize hexagonal LiMnBO3 (h-LMB) through sol-gel technique. The synthesized h-LiMnBO3 have been examined for their physical and electrochemical characteristics by X-ray diffraction analysis (XRD) and Thermal analysis (TG), Scanning electron microscopy (SEM), Raman spectroscopy as well as through charge –discharge cycling. XRD results revealed the existence of hexagonal polymorphs with P6 space group. Stability of h-LiMnBO3 material is analyzed by thermal analysis. SEM image shows spherical shape nanoparticle with the average diameter 50 nm. Raman spectroscopy result indicates the presence of Mn-O vibration. An electrochemical study indicates the sol-gel derived hexagonal LiMnBO3 delivers a first charging capacity of 97.5 mAh g-1 and discharging capacity of 55. 85 mAh g-1 within the potential window of 2V-4.5 V at C/10 rate and retaining a reversible discharge capacity of 42.71 mAh g-1 at the 10th cycle.

scholarly journals Coal bottom ash characterization aiming the incorporation in cellular concrete

2021 ◽  
Vol 26 (3) ◽  
Author(s):  
Fernanda Pacheco ◽  
Michael Anderson Bica Moreira ◽  
Marlova Piva Kuwakowiski ◽  
Feliciane Andrade Breh ◽  
Bernardo Fonseca Tutikian
Keyword(s):  
Silica Fume ◽  
Bottom Ash ◽  
Spherical Shape ◽  
High Rate ◽  
Strength Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Coal Bottom Ash ◽  
The Impact ◽  
Cellular Concrete

ABSTRACT Ahead of the incorporation of residues in concrete composition, there is a decline in the environmental impact of buildings. One of the goals of today’s development is the employment of low-impact energy sources, such as thermoelectric. Thermoelectric industries display a high rate of residues, among which is pointed out coal bottom ash (CBA) (15% total residues), which have density superior to fly ash and accumulates in silos. Considering this scenario, this paper assessed the incorporation feasibility of CBA in the composition of cellular concrete, replacing silica fume. This study comprehended CBA characterization and application. For such, it was performed a scanning electron microscope (SEM) associated with Energy dispersive spectroscopy (EDS) analysis, laser granulometry, X-ray diffraction (XRD), X-ray efflorescence and density. Following the incorporation of the residues in cellular concrete in place of silica fume, it was performed compression strength analysis and SEM anew, evaluating the impact of CBA’s insertion in concrete’s microstructure. The XRD results are complementary to the other analyses. With SEM technique, it was observed the predominance of spherical-shape particles. The compressive strength of CBA concretes was superior to the reference concrete from 0,13 to 0,74MPa.

Growth and Studies of Li (Mn, Co) Oxides for Battery Electrodes

1999 ◽  
Vol 606 ◽  
Author(s):  
S. Nieto-Ramos ◽  
M.S. Tomar ◽  
R.S. Katiyar
Keyword(s):  
Spin Coating ◽  
Annealing Temperature ◽  
Lithium Ion ◽  
Rechargeable Batteries ◽  
Rechargeable Battery ◽  
Oxide Materials ◽  
Synthetic Route ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solution Route

AbstractThere is interest in lithium intercalation oxide materials for cathodes in rechargeable batteries. We have synthesized LiMOx, (where M = Mn, Co) by a less expensive solution route. Reagent grade acetates or hydroxides as precursors for lithium, manganese, and cobalt, respectively, with methoxy ethenol and acetic acid as solvents were used. Powders with different compositions were achieved at annealing temperature below 700 °C. Thin films were deposited by spin coating. X-ray diffraction, Raman spectroscopy, and impedance spectroscopic results are presented. These studies indicate that this synthetic route is suitable to produce good quality lithium-based oxides useful for cathode in lithium-ion rechargeable battery.

scholarly journals Impact of annealing temperature to the performance of hematite based humidity sensor

2019 ◽  
Vol 13 (3) ◽  
pp. 1079 ◽  
Author(s):  
W.R.W. Ahmad ◽  
M.H. Mamat ◽  
Z. Khusaimi ◽  
A.S. Ismail ◽  
M. Rusop
Keyword(s):  
Optical Properties ◽  
Humidity Sensor ◽  
Annealing Temperature ◽  
Annealing Treatment ◽  
Rhombohedral Structure ◽  
X Ray Diffraction ◽  
Structure Morphology ◽  
Diffraction Peaks ◽  
The Impact ◽  
Humidity Range

<span lang="EN-GB">In the present study, hematite (α-Fe<sub>2</sub>O<sub>3</sub>) nanorod structure were grown on fluorine doped tin oxide coated glass substrate via sonicated immersion approach with variation of annealing temperature (350˚C – 600˚C) in one-hour treatment. The impact of varying the temperature of annealing treatment on crystalline phase, structure morphology, optical properties and humidity sensing performance of hematite were examined. X-ray diffraction pattern disclosed a rhombohedral structure with α-phase diffraction peaks. The surface morphology images taken from field emission scanning electron microscopy revealed that the hematite nanorod arrays were grown uniformly in all samples and the average diameters of nanorods were measured in the ranges between 55 and 80 nm. Ultraviolet–visible spectroscopy measurement spectra show that all samples exhibited good optical properties. The hematite humidity sensor sample annealed at 400°C has demonstrated the highest sensitivity response (S=177.78) to humidity range between 40%RH to 90%RH.</span>

Transformation of Structure, Magnetic Properties and Microwave Absorption Capability in Nd-Doped Strontium Hexaferrite

2020 ◽  
Vol 855 ◽  
pp. 255-260
Author(s):  
Mukhtar Effendi ◽  
Efi Solihah ◽  
Candra Kurniawan ◽  
Wahyu Tri Cahyanto ◽  
Wahyu Widanarto
Keyword(s):  
Magnetic Properties ◽  
Microwave Absorption ◽  
Solid State Reaction Method ◽  
Strontium Hexaferrite ◽  
Basic Material ◽  
X Ray Diffraction ◽  
Cell Parameters ◽  
Tetragonal Crystal ◽  
Capability Analysis ◽  
Natural Iron

The synthesize of Nd3+-strontium hexaferrite magnetic material by the solid-state reaction method has been successfully carried out. This study aims to determine the effect of Nd3+ on the structure, magnetic properties, and microwave absorption capability of the material. Preparation of (1-x)SrO:xNd2O3:6Fe2O3 where x = 0, 10, 20, and 30 mol% using basic material in the form of SrCO3 powder, Nd2O3 powder and Fe3O4 from natural iron sand. The characterization includes the X-Ray Diffraction (XRD) examination to determine the crystal structure, the Scanning Electron Microscope (SEM) for exploring the surface morphology, Vibrating Sample Magnetometer (VSM) for the magnetic properties investigation of material, and Vector Network Analyzer (VNA) for microwave absorption capability analysis. The XRD results show that the addition of Nd3+ doping increases the number of SrNdFeO4 phases. The phase has a tetragonal crystal system that has cell parameters a = b = 3.846 Å, and c = 12.594 Å. The magnetic properties of the material showed that the addition of Nd3+ decreased the saturation and remanence magnetization values, whereas the value of the coercivity field increased. Meanwhile, the best microwave absorption occurs in samples with the addition of Nd3+ as much as 0.3 mol, which results in a reflection loss value of -18.9 dB with a frequency bandwidth of 3.9 GHz.

scholarly journals Advances of 2nd Life Applications for Lithium Ion Batteries from Electric Vehicles Based on Energy Demand

2021 ◽  
Vol 13 (10) ◽  
pp. 5726
Author(s):  
Aleksandra Wewer ◽  
Pinar Bilge ◽  
Franz Dietrich
Keyword(s):  
Life Cycle ◽  
Lithium Ion Batteries ◽  
Electric Vehicles ◽  
Energy Demand ◽  
Lithium Ion ◽  
Life Cycles ◽  
Future Research ◽  
Research Areas ◽  
Study Results ◽  
The Impact

Electromobility is a new approach to the reduction of CO2 emissions and the deceleration of global warming. Its environmental impacts are often compared to traditional mobility solutions based on gasoline or diesel engines. The comparison pertains mostly to the single life cycle of a battery. The impact of multiple life cycles remains an important, and yet unanswered, question. The aim of this paper is to demonstrate advances of 2nd life applications for lithium ion batteries from electric vehicles based on their energy demand. Therefore, it highlights the limitations of a conventional life cycle analysis (LCA) and presents a supplementary method of analysis by providing the design and results of a meta study on the environmental impact of lithium ion batteries. The study focuses on energy demand, and investigates its total impact for different cases considering 2nd life applications such as (C1) material recycling, (C2) repurposing and (C3) reuse. Required reprocessing methods such as remanufacturing of batteries lie at the basis of these 2nd life applications. Batteries are used in their 2nd lives for stationary energy storage (C2, repurpose) and electric vehicles (C3, reuse). The study results confirm that both of these 2nd life applications require less energy than the recycling of batteries at the end of their first life and the production of new batteries. The paper concludes by identifying future research areas in order to generate precise forecasts for 2nd life applications and their industrial dissemination.

scholarly journals The impact of point defects in n-type GaN layers on thermal decomposition of InGaN/GaN QWs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mikolaj Grabowski ◽  
Ewa Grzanka ◽  
Szymon Grzanka ◽  
Artur Lachowski ◽  
Julita Smalc-Koziorowska ◽  
...  
Keyword(s):  
Quantum Wells ◽  
High Temperatures ◽  
Point Defects ◽  
X Ray Diffraction ◽  
Helium Ions ◽  
X Ray ◽  
Sapphire Substrates ◽  
Transmission Electron ◽  
The Impact ◽  
Ingan Quantum Wells

AbstractThe aim of this paper is to give an experimental evidence that point defects (most probably gallium vacancies) induce decomposition of InGaN quantum wells (QWs) at high temperatures. In the experiment performed, we implanted GaN:Si/sapphire substrates with helium ions in order to introduce a high density of point defects. Then, we grew InGaN QWs on such substrates at temperature of 730 °C, what caused elimination of most (but not all) of the implantation-induced point defects expanding the crystal lattice. The InGaN QWs were almost identical to those grown on unimplanted GaN substrates. In the next step of the experiment, we annealed samples grown on unimplanted and implanted GaN at temperatures of 900 °C, 920 °C and 940 °C for half an hour. The samples were examined using Photoluminescence, X-ray Diffraction and Transmission Electron Microscopy. We found out that the decomposition of InGaN QWs started at lower temperatures for the samples grown on the implanted GaN substrates what provides a strong experimental support that point defects play important role in InGaN decomposition at high temperatures.

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