Structure and Microstructure Properties of Ball Milled Fe-Zn

Nanocrystalline Fe10 %Zn and Fe30 %Zn alloys have been prepared from pure elemental powders by mechanical alloying processing in a high energy planetary ball-mill. Microstructural, structural, and magnetic characterizations of the powders were investigated by X-ray diffraction, and vibrating sample magnometer. The crystallite size reduction to the nanometer scale is accompanied by an increase in the atomic level strain. The reaction between Fe and Zn leads to the formation of a bcc Fe(Zn) solid solution with a lattice parameter close to (0.2912 nm for Fe30 %Zn and 0,2885 nm for Fe10 %Zn) after 5 h of milling. The complete dissolution of the elemental Zn powders in the a-Fe lattice gives rise to the formation of a highly disordered Fe(Zn) solid solution, where a-Fe(Zn) nanograins have a crystallite size of (229,29 Å for Fe10 %Zn (24 h) 30,09 Å for Fe30 %Zn (24 h), on prolonged milling time. The coercivity and magnetization values are 18,90 (Fe10 %Zn)Oe and 26,59 (Fe30 %Zn) emu/g, respectively, after 24 h of milling. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3514

Microstructure Characterization of Nanocrystalline Ni₅₀Ti₅₀ Alloy Prepared Via Mechanical Alloying Method Using the Rietveld Refinement Method Applied to the X-Ray Diffraction

Using the Rietveld refinement, we analysed the structural evolution of Ni₅₀Ti₅₀ alloy prepared by mechanical alloying method. The elemental Ti and Ni powders are milled during different milling times (0, 1, 3, 6, 24, and 72 hours) in a high-energy planetary ball mill (Pulverisette 7 premium line). The milled powder specimens were characterized with x-ray Philips X,Pert diffractometer equipped with CuKα radiation source (λCu = 0.15418 nm). We refined the structure of compounds using the MAUD program, and we found structural parameters such as the atomic positions (x, y, z), symmetry, and a space group. Moreover, microstructural parameters such as the lattice parameters (a, b, c), the average crystallite size , microstrains ¹/², the average number of compacted layers, and the phase percentages were also determined. According to the results, at the initial stages of milling (typically of 1–3 h), the structure consists of Ni-based solid solution [f.c.c.-Ni (Ti)], Ti-based solid solution [h.c.p.-Ti (Ni)], and amorphous phase (??40 wt.%). Based on the data evaluated during milling, the nanocrystalline NiTi-martensite (B19') and NiTi-austenite (B2) phases are initially formed from the primary materials and from the amorphous phase.Используя ритвелдовский метод полнопрофильного анализа структуры, мы анализировали структурную эволюцию сплава Ni₅₀Ti₅₀, подготовленного методом механического легирования. Элементные порошки титана и никеля мелются в течение различных времён измельчения (0, 1, 3, 6, 24 и 72 часа) в высокоэнергетической внутришлифовальной планетарной шаровой мельнице тонкого помола (Pulverisette 7 премиальной линии). Намолоченные порошковые образцы для испытания были охарактеризованы рентгеновским дифрактометром Philips X,Pert, оборудованным источником излучения CuKα (λCu = 0,15418 нм). Мы уточнили строение соединений, используя программу MUAD (анализа материалов с использованием дифракции), и мы нашли структурные параметры типа атомных позиций (x, y, z), симметрию и пространственную группу. Кроме того, микроструктурные параметры типа параметров решётки (a, b, c), средний размер кристаллита , микродеформации ¹/², среднее число уплотнённых слоёв и фазовые процентные содержания были также определены. Согласно результатам, на начальных стадиях размалывания (обычно 1–3 часа), структура состоит из твёрдого раствора на основе никеля [ГЦК-никель (Ti)], твёрдого раствора на основе титана [ГПУ-титан (Ni)] и аморфной фазы (≈ 40 вес.%). Основываясь на данных, оценённых в течение размалывания, выяснено, что нанокристаллические фазы NiTi-мартенсита (B19') и NiTi-аустенита (B2) первоначально сформировались из первичных материалов и из аморфной фазы.Використовуючи Рітвелдову методу повнопрофільної аналізи структури, ми аналізували структурну еволюцію стопу Nі₅₀Tі₅₀, підготовленого методою механічного леґування. Елементні порошки титану та ніклю мелються протягом різних часів здрібнювання (0, 1, 3, 6, 24 і 72 години) у високоенергетичному внутрішньошліфувальному планетарному кульовому млині тонкого млива (Pulverіsette 7 преміяльної лінії). Намолочені порошкові зразки для випробування були охарактеризовані рентґенівським дифрактометром Phіlіps X,Pert, обладнаним джерелом випромінення CuKα (λCu = 0,15418 нм). Ми уточнили будову сполук, використовуючи програму MUAD (аналізи матеріялів з використанням дифракції), і ми знайшли структурні параметри типу атомових позицій (x, y, z), симетрію та просторову групу. Крім того, мікроструктурні параметри типу параметрів ґратниці (a, b, c), середній розмір кристаліта , мікродеформації ¹/², середнє число ущільнених шарів і фазові процентні вмісти були також визначені. Згідно з результатами, на початкових стадіях розмелювання (звичайно 1–3 години), структура складається із твердого розчину на основі ніклю [ГЦК-нікель (Tі)], твердого розчину на основі титану [ГЩП-титан (Nі)] і аморфної фази (? 40 ваг.%). Ґрунтуючись на даних, оцінених протягом розмелювання, з’ясовано, що нанокристалічні фази NіTі-мартенситу (B19') і NіTі-аустениту (B2) спочатку сформувалися з первинних матеріялів і з аморфної фази

Effect of Graphite Particle Size on Structural and Morphological Characteristics of Carbon Nanotubes Grown by Microwave Oven

The influence of graphite particle size on the formation and diameter of carbon nanotubes (CNTs), is investigated. graphite with different diameters are used for the growth of CNTs by a cost-effective method using a microwave oven. Morphological observations by field emission scanning electron microscopy (FESEM) reveal consistently that smaller graphite diameter generates CNTs with a different diameter. Raman spectroscopy indicates that the full width at half maximum (FWHM) of G, D and 20 bands decreases gradually with increasing CNTs diameter. Furthermore, CNTs diameter is found to be inversely proportional to (002) line widt

The effects of the ambient liquid medium on the ablation efficiency, size and stability of silver nanoparticles prepared by pulse laser ablation in liquid technique

Silver (Ag) nanoparticles (NPs) were synthesized by pulsed laser (Nd:YAG, 1064 nm) ablation of individual target in various solutions. The influence of deionized water (DIW), ethanol and Polyvinylpyrrolidone (PVP) as ambient medium on the fundamental aspects such as ablation efficiency, particle size and stability of Ag NPs was studied. UV-vis spectrophotometer and transmission electron microscopy (TEM) were used to study the optical characterization and morphological analysis of all the synthesized samples, respectively. Preparation in DIW was carried out as a reference sample. The experiments demonstrated that ablation efficiency and stability of NPs in ethanol medium are lowest than those prepared in PVP medium and the reference sample. PVP medium led to higher stability, lower ablation efficiency and finer average particle size compared to reference sample

Facile Synthesis of Fe3O4−SiO2 Nanocomposites for Wastewater Treatment

This is the final version. Available on open access from Wiley via the DOI in this recordData Availability Statement: The data that support the findings of this study are available from the corresponding author upon reasonable request.Water constitutes ≈70–90% of the organism's body by mass and is highly important for its survival. Water contains a variety of chemical contaminants introduced by various sectors, resulting in contamination that has a direct impact on the ecosystem. Various approaches are in practice to tackle these issues. Among these, semiconductor photocatalysis appears to be the cutting-edge technology for the degradation of wastewater contaminants. Herein, the fabrication of Fe3O4−SiO2 nanocomposite via facile co-precipitation and Stober methods are reported. Various characterization techniques are employed for the structural elucidation, morphology, crystallinity, and stability of the as-prepared composite. The nanocomposite is employed in catalytic and photocatalytic applications toward the removal of methylene blue (MB) and methyl orange (MO) dyes from a comparative perspective. It is observed that the composite can remove about 93% of MB and 51% of MO within 7 and 6 h, respectively. These findings indicate that the nanocomposite has a higher MB removal effectiveness than the MO. This trend can be accredited to the difference in the chemical structure of both dyes. The nanocomposite is also evaluated for antioxidant and antileishmanial activity, and it is shown to be quite effective even at very low concentrations.Engineering and Physical Sciences Research Council (EPSRC

Photo-electrochemically synthesized light emtting nanoporous silicon based UV photodetector: influence of current density

Nanoporous silicon (n-PSi) with diverse morphologies was prepared on silicon (Si) substrate via photo-electrochemical etching technique. The role of changing current density (15, 30 and 45 mA cm−2) on the structure, morphology and optical properties was determined. As-prepared samples were systematically characterized using XRD, FESEM, AFM and photoluminescence measurements. Furthermore, the achieved n-PSi sample was used to make metal–semiconductor–metal (MSM) UV photodetector. The performance of these photodetectors was evaluated upon exposing to visible light of wavelength 530 nm (power density 1.55 mW cm−2), which exhibited very high sensitivity of 150.26 with a low dark current. The achieved internal photoconductive gain was 2.50, the photoresponse peak was 1.23 A W−1 and the response time was 0.49 s and the recovery time was 0.47 s. Excellent attributes of the fabricated photodetectors suggest that the present approach may provide a cost effective and simple way to obtain n-PSi suitable for sundry applications

Photophysical performance of radio frequency sputtered Pt/n-PSi/ZnO NCs/Pt photovoltaic photodetectors

The effect of the annealing temperature on the photoelectrical properties of the nanoporous silicon/zinc oxide nanocrystallites-based (Pt/n-PSi/ZnO NCs/Pt) photodetector was investigated. Different morphologies of 3D ZnO were synthesized onto the n-PSi substrates via radio frequency (RF) sputtering in the absence of a catalyst. The synthesis of ZnO NCs was controlled by varying the growth temperature between 600–700 °C and 800–900 °C. The effect of the synthesis temperature on the structural, morphological, and optical properties of the n-PSi/ZnO NCs was systematically studied using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), atomic force microscopy (AFM), and photoluminescence spectroscopy (PL) techniques. The roughness was found to be dependent on the anodization current density. The optimal n-PSi/ZnO NCs-based metal-semiconductor-metal UV detector (MSM) was fabricated at 700 °C. The fabricated device showed a high sensitivity of 1007.14, an internal photoconductive gain of 11.07, and a responsivity of 5.99 A/W with a low dark current when illuminated with 380 nm light (1.55 mW/cm2) at +5 V bias voltage. In addition, the response and recovery times were determined to be 0.34 and 0.22 s, respectively. This approach offers a cost-effective substrate and simple synthesis method to improve the growth of the n-PSi/ZnO NCs and demonstrates the successful fabrication of nanoscale photodetectors with potential application in nano-optics devices

Structural characterisation of carbon nanotubes in the presence of a Ni catalyst

Multi-wall carbon nanotubes (MWNTs) grown by chemical vapour deposition (CVD) of an ethene / hydrogen gas mixture on alumina supported and unsupported nickel catalysts for 10, 20 and 120 minutes at 600oC and 700oC are compared. Nano-scale nickel particles were identified at the tube ends and also within the main body of the tubes. The particles exhibited comet like structures suggesting the metal to be highly mobile if not molten during processing. HREM observations demonstrate the carbon planes to be parallel to the nickel particle surfaces, while eventually becoming drawn out to define the carbon tube walls. The tubes are generally found to emanate from larger encapsulated nickel particles. A growth mechanism involving the propulsion of mobile nickel through the precipitation of the carbon is discussed