scholarly journals Role of Nanocrystallites of Al-Based Glasses and H2O2 in Degradation Azo Dyes

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 39
Author(s):  
Qi Chen ◽  
Zhicheng Yan ◽  
Hao Zhang ◽  
KiBuem Kim ◽  
Weimin Wang
Keyword(s):  
Metallic Glasses ◽  
Azo Dye ◽  
Amorphous Matrix ◽  
Nano Scale ◽  
Transmission Electron ◽  
Melt Spun ◽  
Degradation Ability ◽  
Tem Transmission Electron Microscopy ◽  
Dye Solutions

Al-based metallic glasses have a special atomic structure and should have a unique degradation ability in azo dye solutions. The Al88Ni9Y3 (Y3), Al85Ni9Y6 (Y6) and Al82Ni9Y9 (Y9) glassy ribbons are melt spun and used in degrading methyl orange (MO) azo dye solution with adding H2O2. With increasing cY, the as-spun ribbons have an increasing GFA (glass formability) and gradually decreased the degradation rate of MO solution. TEM (transmission electron microscopy) results show that the Y3 ribbon has nano-scale crystallites, which may form the channels to transport elements to the surface for degrading the MO solution. After adding H2O2, the degradation efficiency of Al-based glasses is improved and the Y6 ribbon has formed nano-scale crystallites embedded in the amorphous matrix and it has the largest improvement in MO solution degradation. These results indicate that forming nano-scale crystallites and adding H2O2 are effective methods to improve the degradation ability of Al-based glasses in azo dye solutions.

scholarly journals Observation of Nano-Scale Microstructures in Melt-Spun Al-Ni-Gd Metallic Glasses

Materia Japan ◽  
2006 ◽  
Vol 45 (12) ◽  
pp. 860-860
Author(s):  
Shoichi Hirosawa ◽  
Tatsuo Sato ◽  
Gary J. Shiflet ◽  
Kenji Matsuda
Keyword(s):  
Metallic Glasses ◽  
Nano Scale ◽  
Melt Spun

Precipitation of Zr2Cu Stable Crystalline Phase from Zr70Cu27.5Rh2.5 Amorphous Alloy

2006 ◽  
Vol 979 ◽  
Author(s):  
David Cushman ◽  
Junji Saida ◽  
Chunfei Li
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Metallic Glasses ◽  
Crystalline Phase ◽  
Crystallization Process ◽  
Amorphous Matrix ◽  
Nucleation Process ◽  
Transmission Electron ◽  
The Stability ◽  
Icosahedral Quasicrystalline

AbstractThe crystallization process of Zr70Cu27.5Rh2.5 metallic glass was studied with Transmission Electron Microscopy (TEM). In contrast to previous studies where the precipitation of metastable icosahedral quasicrystalline (IQC) particles is of the interest, we designed the present work to focus on the nucleation process of the stable Zr2Cu crystalline phase. It has been found that the alloy consists of IQC particles distributed in amorphous matrix prior to the precipitation of the Zr2Cu stable crystalline phase and Zr2Cu nucleates from the amorphous matrix. The encounter of the IQC phase with Zr2Cu transforms the former into the latter so quickly that no interface between them was found in the present experiment. These insights provide the basis for a discussion of the stability of metallic glasses and the IQC particles.

Deformation-induced crystallization and amorphization of Al-based metallic glasses

2002 ◽  
Vol 740 ◽  
Author(s):  
Rainer J. Hebert ◽  
John H. Perepezko
Keyword(s):  
Thermal Stability ◽  
Metallic Glasses ◽  
Applied Load ◽  
Amorphous Matrix ◽  
Main Requirement ◽  
Induced Stress ◽  
Structural Applications ◽  
Melt Spun ◽  
Stress States ◽  
Induced Crystallization

ABSTRACTA main requirement for the application of nanostructured materials for structural applications is their thermal stability. Structural materials are often exposed to mechanically-induced stress states. Nanomaterials for structural applications should therefore retain their microstructure not only within a defined temperature range but also under applied load. Cold-rolling experiments with melt-spun Al87Ni10Ce3 ribbons containing a dispersion of nanocrystallites in an amorphous matrix demonstrate that during the continued deformation through repeated rolling and folding crystallization as well as amorphization reactions could be induced. The results indicate that in addition to the microstructure control through annealing of precursor materials, deformation processing represents an effective approach to the synthesis of amorphous and nanophase composite materials.

Formation and Properties of Amorphous/Crystalline Ductile Composites in Ni-Ag-P Immiscible Alloys

2012 ◽  
Vol 186 ◽  
pp. 216-221 ◽  
Author(s):  
Krzysztof Ziewiec ◽  
Piotr Malczewski ◽  
Grzegorz Boczkal ◽  
Krystian Prusik
Keyword(s):  
Tensile Strength ◽  
Amorphous Matrix ◽  
Silver Content ◽  
Tensile Tests ◽  
Glass Forming ◽  
Loading Direction ◽  
Transmission Electron ◽  
Melt Spun ◽  
Melt Spun Ribbons ◽  
Lower Tensile Strength

The aim of the work was to investigate the influence of silver as a modifying constituent on structure formation in Ni-P based glass forming matrix. Nickel-phosphorus-based Ni80P20, Ni78Ag2P20 and Ni76Ag4P20 alloys were prepared from 99.95 wt % Ni, 99.95 wt % Ag, and Ni-P master alloy. The alloys were melt-spun in helium. The microstructure of the melt-spun ribbons was investigated by XRD, a light microscope and a transmission electron microscope. Then the tensile tests were performed. The alloys with silver show lower tensile strength with respect to the fully amorphous Ni80P20 ribbon. The ductility of the amorphous matrix melt-spun Ni78Ag2P20 and Ni76Ag4P20 alloys was improved by addition of silver forming fcc-Ag precipitates in comparison with Ni80P20amorphous alloy. SEM observations of the fracture surfaces show different character of the fractured samples. The pattern and the number of the crack lines changes, depending on the silver content. For the fully amorphous Ni80P20 alloy simple brittle cracks are observed, however the alloys with silver content show more developed surfaces near the fractured regions and form crack lines arranged 60° with loading direction.

The Effect of Heat Treatment on the Corrosion Behavior of Amorphous Mg–Ni–Nd Alloys

1999 ◽  
Vol 14 (4) ◽  
pp. 1638-1644 ◽  
Author(s):  
C. H. Kam ◽  
Y. Li ◽  
S. C. Ng ◽  
A. Wee ◽  
J. S. Pan ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Corrosion Behavior ◽  
Amorphous Matrix ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Heat Treated ◽  
Uniform Dispersion ◽  
Melt Spun

The effect of heat treatment on the corrosion behavior of seven amorphous melt-spun Mg–Ni–Nd alloys containing 10–20 at.% Ni and 5–15 at.% Nd has been studied. Hydrogen evolution testing was used to determine the dissolution rate of the heat-treated specimens immersed in a 3% NaCl solution saturated with Mg(OH)2. The dissolution rates of the partially crystallized specimens were found to be lower than those of the untreated specimens, while the fully crystallized specimens exhibited marked deterioration of corrosion resistance. X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies on the heat-treated specimens revealed precipitation of Mg3Nd, Mg12Nd, and Mg2Ni phases during the crystallization. TEM results show that the partially crystallized structure consists of uniform dispersion of either Mg3Nd or Mg2Ni in the amorphous matrix. In contrast, multiple phases precipitate in the fully crystallized specimen.

Crystallization of ternary Zr-based glasses—Kinetics and microstructure

1998 ◽  
Vol 13 (2) ◽  
pp. 504-517 ◽  
Author(s):  
G. K. Dey ◽  
R. T. Savalia ◽  
E. G. Baburaj ◽  
S. Banerjee
Keyword(s):  
Metallic Glasses ◽  
Composition Range ◽  
Amorphous Matrix ◽  
Primary Crystallization ◽  
Nucleation And Growth ◽  
Crystal Nucleation ◽  
Cubic Phase ◽  
Eutectic Crystallization ◽  
Kinetics Of

The effect of ternary addition on the thermal stability and the sequence and the kinetics of crystallization of metallic glasses Zr76Fe(24−x)Nix (x = 0, 4, 8, 12, 16, 20, 24) have been examined. It has been found that the surface crystallization occurs in the composition range 16 < x < 20, leading to the formation of an ordered Fe-rich (Fe, Ni)3Zr cubic phase, followed by the transformation of the bulk to a mixture of α−Zr and Zr2Ni. Crystallization of alloys containing 12 to 20% Fe occurs at lower temperatures by primary crystallization of Zr3(Fe, Ni), followed by decomposition of the remaining amorphous matrix by eutectic crystallization giving rise to α−Zr + Zr2Ni. At higher temperatures these alloys transform polymorphically to Zr3(Fe, Ni) in which Ni partially substitutes Fe in the Zr3Fe lattice. Copious nucleation of Zr3(Fe, Ni) phase in these alloys, leading to the formation of a nanophase structure, has been observed. This is consistent with the prediction of increasing nucleation rate for Fe-rich compositions. The crystal nucleation and growth kinetics have been examined for primary, eutectic, and polymorphic crystallization processes. The observed nucleation and growth behaviors have been rationalized by considering the role of the quenched in nuclei and the activation energies of nucleation and growth.

On Future Directions in Pathology

1982 ◽  
Vol 40 ◽  
pp. 274-277
Author(s):  
Benjamin F. Trump ◽  
Irene K. Berezesky ◽  
Raymond T. Jones
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Clinical Pathology ◽  
Future Directions ◽  
Diagnostic Pathology ◽  
The Past ◽  
Transmission Electron ◽  
Organ Systems ◽  
The Many

The role of electron microscopy and associated techniques is assured in diagnostic pathology. At the present time, most of the progress has been made on tissues examined by transmission electron microscopy (TEM) and correlated with light microscopy (LM) and by cytochemistry using both plastic and paraffin-embedded materials. As mentioned elsewhere in this symposium, this has revolutionized many fields of pathology including diagnostic, anatomic and clinical pathology. It began with the kidney; however, it has now been extended to most other organ systems and to tumor diagnosis in general. The results of the past few years tend to indicate the future directions and needs of this expanding field. Now, in addition to routine EM, pathologists have access to the many newly developed methods and instruments mentioned below which should aid considerably not only in diagnostic pathology but in investigative pathology as well.

Transmission Electron Microscopy studies of texture of Cr underlayer of magnetic recording hard disk

1991 ◽  
Vol 49 ◽  
pp. 580-581
Author(s):  
L. Tang ◽  
G. Thomas ◽  
M. R. Khan ◽  
S. L. Duan
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Magnetic Recording ◽  
Magnetic Thin Films ◽  
Magnetic Films ◽  
Substrate Bias ◽  
Epitaxial Relationship ◽  
Transmission Electron

Cr thin films are often used as underlayers for Co alloy magnetic thin films, such as Co1, CoNi2, and CoNiCr3, for high density longitudinal magnetic recording. It is belived that the role of the Cr underlayer is to control the growth and texture of the Co alloy magnetic thin films, and, then, to increase the in plane coercivity of the films. Although many epitaxial relationship between the Cr underlayer and the magnetic films, such as ﹛1010﹜Co/ {110﹜Cr4, ﹛2110﹜Co/ ﹛001﹜Cr5, ﹛0002﹜Co/﹛110﹜Cr6, have been suggested and appear to be related to the Cr thickness, the texture of the Cr underlayer itself is still not understood very well. In this study, the texture of a 2000 Å thick Cr underlayer on Nip/Al substrate for thin films of (Co75Ni25)1-xTix dc-sputtered with - 200 V substrate bias is investigated by electron microscopy.

Transmission Electron Microscopy of Evaporated Perylene Thin Films

1990 ◽  
Vol 48 (2) ◽  
pp. 336-337
Author(s):  
C. Ewins ◽  
J.R. Fryer
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Molecular Electronics ◽  
High Vacuum ◽  
Amorphous Layer ◽  
Electric Heater ◽  
Transmission Electron ◽  
Polycyclic Aromatic

The preparation of thin films of organic molecules is currently receiving much attention because of the need to produce good quality thin films for molecular electronics. We have produced thin films of the polycyclic aromatic, perylene C10H12 by evaporation under high vacuum onto a potassium chloride (KCl) substrate. The role of substrate temperature in determining the morphology and crystallography of the films was then investigated by transmission electron microscopy (TEM).The substrate studied was the (001) face of a freshly cleaved crystal of KCl. The temperature of the KCl was controlled by an electric heater or a cold finger. The KCl was heated to 200°C under a vacuum of 10-6 torr and allowed to cool to the desired temperature. The perylene was then evaporated over a period of one minute from a molybdenum boat at a distance of 10cm from the KCl. The perylene thin film was then backed with an amorphous layer of carbon and floated onto copper microscope grids.

Fine structure and possible functions of the hermaphrodite duct of some pulmonate snails (Mollusca: Gastropoda)

1990 ◽  
Vol 48 (3) ◽  
pp. 68-69
Author(s):  
Alan N. Hodgson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Seminal Vesicle ◽  
Reproductive Biology ◽  
Light Microscope ◽  
Light Microscope Level ◽  
Transmission Electron ◽  
Standard Techniques

The hermaphrodite duct of pulmonate snails connects the ovotestis to the fertilization pouch. The duct is typically divided into three zones; aproximal duct which leaves the ovotestis, the middle duct (seminal vesicle) and the distal ovotestis duct. The seminal vesicle forms the major portion of the duct and is thought to store sperm prior to copulation. In addition the duct may also play a role in sperm maturation and degredation. Although the structure of the seminal vesicle has been described for a number of snails at the light microscope level there appear to be only two descriptions of the ultrastructure of this tissue. Clearly if the role of the hermaphrodite duct in the reproductive biology of pulmonatesis to be understood, knowledge of its fine structure is required.Hermaphrodite ducts, both containing and lacking sperm, of species of the terrestrial pulmonate genera Sphincterochila, Levantina, and Helix and the marine pulmonate genus Siphonaria were prepared for transmission electron microscopy by standard techniques.

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