scholarly journals Effect of Alternating Magnetic Field on the Fatigue Behaviour of EN8 Steel and 2014-T6 Aluminium Alloy

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 984 ◽  
Author(s):  
Akram ◽  
Babutskyi ◽  
Chrysanthou ◽  
Montalvão ◽  
Pizurova
Keyword(s):  
Magnetic Field ◽  
Electron Microscopy ◽  
Fatigue Behaviour ◽  
Alternating Magnetic Field ◽  
X Ray Diffraction ◽  
Secondary Precipitation ◽  
Transmission Electron ◽  
Fatigue Endurance ◽  
Fracture Features ◽  
Compressive Residual Stresses

The application of an alternating magnetic field (0.54 T) was observed to lead to an improvement in the fatigue endurance and an increase in Vickers microhardness and tensile strength of both EN8 steel and AA2014-T6 alloy. Fractography using scanning electron microscopy showed evidence of more ductile fracture features after treatment in contrast to untreated samples. The results of X-ray diffraction indicated formation of more compressive residual stresses following treatment; while examination by transmission electron microscopy showed evidence of fewer dislocations. In the case of the AA2014-T6 alloy; Guinier-Preston (GP) zones were also generated by the alternating magnetic field. However; the temperature increase during the treatment was too low to explain these observations. The results were attributed to the non-thermal effect of the alternating magnetic field treatment that led to depinning and movement of dislocations and secondary precipitation of copper.

Superconductivity of Dc Reactive Magnetron Sputtered Epitaxial TiN/NbN Superlattices

1992 ◽  
Vol 275 ◽  
Author(s):  
M. Shinn ◽  
B. -S. Hong ◽  
S. A. Barnett
Keyword(s):  
Magnetic Field ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Film Surface ◽  
Wavelength Dependence ◽  
Reactive Magnetron ◽  
Superconducting Transition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

ABSTRACTEpitaxial B1-structure TiN/NbN superlattices have been grown by reactive magnetron sputtering On MgO(001). X-ray diffraction and transmission electron microscopy (TEM) diffraction spectra exhibited up to nine orders of superlattice reflections, indicating that the superlattice interfaces were relatively sharp. TEM images also showed well-defined layers. The superlattice wavelength (∧) dependence of the superconducting transition temperature (Tc), critical Current density (Jc), and electrical resistivity (ρ) have been investigated. Tc values increased from 12 K to 17 K with increasing ∧. Jc in a magnetic field perpendicular to the film surface ranged from 104 to 106 A/cm2, increasing with increasing wavelength and decreasing with increasing applied magnetic field. Jc in a field parallel to the film surface was > 10 times higher, ≈ 107 A/cm2. The resistivity exhibited different ∧ dependencies in three different A ranges.

Magnetic cluster developement in In1−x MnxSb semiconductor alloys

Open Physics ◽  
2010 ◽  
Vol 8 (4) ◽  
Author(s):  
Lidia Rednic ◽  
Iosif Deac ◽  
Eugen Dorolti ◽  
Marin Coldea ◽  
Vasile Rednic ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Magnetic Measurements ◽  
Semiconductor Alloys ◽  
X Ray Diffraction ◽  
Magnetic Cluster ◽  
X Ray ◽  
Small Magnetic Field ◽  
Transmission Electron

AbstractX-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscopy (TEM) and magnetic measurements as a function of applied magnetic field and temperature for In1−x MnxSb (0.05≤x≤0.2) system are reported. Magnetic measurements performed at high and small magnetic field in ZFC and FC indicate the coexistence of ferromagnetic In1−x MnxSb solid solution and two types of magnetic cluster: ferromagnetic MnSb and ferrimagnetic Mn2Sb. XPS valence band and Mn 2p core level spectra have confirmed the presence of MnSb and Mn2Sb phases. TEM images show some manganese antimonide phase microinclusions with dimension between (30–40) nm.

scholarly journals Alignment ofTiO2(Anatase) Crystal of Dye-Sensitized Solar Cells by External Magnetic Field

2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Na-Yeong Hong ◽  
Hyunwoong Seo ◽  
Min-Kyu Son ◽  
Soo-Kyoung Kim ◽  
Song-Yi Park ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electron Microscopy ◽  
Electrochemical Impedance ◽  
Dye Sensitized Solar Cells ◽  
Energy Conversion Efficiency ◽  
X Ray Diffraction ◽  
Solar Simulator ◽  
Dye Sensitized ◽  
Transmission Electron ◽  
The Magnetic Field

In this study, magnetic field (B) was applied on TiO2(anatase) of dye-sensitized solar cell (DSC) for alignment of crystal. Magnetic field was applied on TiO2when deposited TiO2on the fluorine tin oxide (FTO) was dried at 373 K for crystalline orientation. And applying time ofBwas varied 0~25 min. Characteristics of the magnetic field applied TiO2films were analyzed by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), and electrochemical impedance spectroscopy (EIS). Current-voltage characteristics were also analyzed using solar simulator, and it was confirmed that the energy conversion efficiency of 41% was increased. Finally, it was identified that the magnetic field affected orientation of TiO2, resulting in the enhancement of the performance of the DSC.

Highly aligned magnetic composite nanofibers fabricated by magnetic-field-assisted electrospinning PAN/FeCo solution

2018 ◽  
Vol 31 (2) ◽  
pp. 230-237 ◽  
Author(s):  
Linyu Mei ◽  
Huiyu Chen ◽  
Yunpeng Shao ◽  
Junyuan Wang ◽  
Yaqing Liu
Keyword(s):  
Magnetic Field ◽  
Electron Microscopy ◽  
Composite Nanofibers ◽  
Fiber Axis ◽  
Magnetic Composite ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Transmission Electron ◽  
Composite Nanofiber ◽  
Nanocomposite Fibers

Composite nanofiber meshes of well-aligned polyacrylonitrile (PAN)/FeCo nanofibers containing nanoparticles (NPs) were successfully fabricated by a magnetic-field-assisted electrospinning technology, which was confirmed to be a favorable method for the preparation of aligned composite nanofibers in this article. Meanwhile, FeCo NPs, with a particle size of approximately 60 nm, were synthesized using a hydrothermal route. The nanocomposite fibers were prepared by an electrospun solution of PAN containing 0, 2, 4, and 6 wt% NPs. The as-spun nanofibers were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and vibrating sample magnetometer. Both the diameters and the degree of alignment of the composite nanofibers decreased with the increase in voltage and increased with the increase in FeCo content. The composite nanofibers exhibited superior ordered performance, with the highest alignment value being 97%. Due to the highly ordered alignment structures, the composite nanofiber meshes showed large anisotropic magnetic property. In particular, the saturation magnetization of the composite nanofiber films in the parallel and perpendicular directions of the fiber axis were 42 emu/g and 19.5 emu/g, respectively. Meanwhile, the remanence also exhibited distinction in different directions (parallel: 2.01 emu/g; perpendicular: 0.86 emu/g).

scholarly journals Synthesis of Poly(N-vinylcaprolactam)-Grafted Magnetite Nanocomposites for Magnetic Hyperthermia

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
A. Morfin-Gutiérrez ◽  
H. Iván Meléndez-Ortiz ◽  
B. A. Puente-Urbina ◽  
L. A. García-Cerda
Keyword(s):  
Magnetic Field ◽  
Electron Microscopy ◽  
Magnetic Hyperthermia ◽  
Heating Equipment ◽  
X Ray Diffraction ◽  
Hyperthermia Treatment ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir ◽  
Vibration Sample Magnetometry

In this study, the synthesis, characterization, and application of poly(N-vinylcaprolactam)-grafted magnetite nanocomposites for magnetic hyperthermia are reported. Superparamagnetic magnetite nanoparticles (MagNPs) with sizes in the range of 10–16 nm were synthesized by the coprecipitation method and then functionalized with vinyltrimethoxysilane (VTMS). MagNPs-VTMS coated with poly(N-vinylcaprolactam) (PNVCL) were prepared by free radical polymerization. The obtained materials were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), vibration sample magnetometry (VSM), and Fourier transform infrared spectroscopy (FT-IR). The heating ability was evaluated under a magnetic field using a solid state induction heating equipment at 10.2 kA/m and 362 kHz. The MagNPs-PNVCL nanocomposites showed a behavior close to superparamagnetic materials, which is appropriated for magnetic hyperthermia treatment; in concentrations of 8 mg/mL, they were able to heat up, increasing the temperature up to 42°C in a period of time lower than 10 minutes.

scholarly journals Assessing the hyperthermic properties of magnetic heterostructures: the case of gold–iron oxide composites

2016 ◽  
Vol 6 (6) ◽  
pp. 20160058 ◽  
Author(s):  
Elvira Fantechi ◽  
Paula M. Castillo ◽  
Erika Conca ◽  
Francesca Cugia ◽  
Claudio Sangregorio ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Iron Oxide ◽  
Magnetic Fluid ◽  
Potassium Citrate ◽  
Alternating Magnetic Field ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Magnetic Fluid Hyperthermia ◽  
Transmission Electron ◽  
Oxide Composites

Gold–iron oxide composites were obtained by in situ reduction of an Au(III) precursor by an organic reductant (either potassium citrate or tiopronin) in a dispersion of preformed iron oxide ultrasmall magnetic (USM) nanoparticles. X-ray diffraction, transmission electron microscopy, chemical analysis and mid-infrared spectroscopy show the successful deposition of gold domains on the preformed magnetic nanoparticles, and the occurrence of either citrate or tiopronin as surface coating. The potential of the USM@Au nanoheterostructures as heat mediators for therapy through magnetic fluid hyperthermia was determined by calorimetric measurements under sample irradiation by an alternating magnetic field with intensity and frequency within the safe values for biomedical use. The USM@Au composites showed to be active heat mediators for magnetic fluid hyperthermia, leading to a rapid increase in temperature under exposure to an alternating magnetic field even under the very mild experimental conditions adopted, and their potential was assessed by determining their specific absorption rate (SAR) and compared with the pure iron oxide nanoparticles. Calorimetric investigation of the synthesized nanostructures enabled us to point out the effect of different experimental conditions on the SAR value, which is to date the parameter used for the assessment of the hyperthermic efficiency.

A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

1982 ◽  
Vol 40 ◽  
pp. 722-723 ◽  
Author(s):  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

Epitaxy and texture analysis of Bi-Sr-Ca-Cu-O thin films on (100) MgO using Transmission Electron Microscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 68-69
Author(s):  
J. T. Sizemore ◽  
D. G. Schlom ◽  
Z. J. Chen ◽  
J. N. Eckstein ◽  
I. Bozovic ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Critical Currents ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Cell Axis ◽  
Transmission Electron ◽  
Synthesis Procedure

Investigators observe large critical currents for superconducting thin films deposited epitaxially on single crystal substrates. The orientation of these films is often characterized by specifying the unit cell axis that is perpendicular to the substrate. This omits specifying the orientation of the other unit cell axes and grain boundary angles between grains of the thin film. Misorientation between grains of YBa2Cu3O7−δ decreases the critical current, even in those films that are c axis oriented. We presume that these results are similar for bismuth based superconductors and report the epitaxial orientations and textures observed in such films.Thin films of nominally Bi2Sr2CaCu2Ox were deposited on MgO using molecular beam epitaxy (MBE). These films were in situ grown (during growth oxygen was incorporated and the films were not oxygen post-annealed) and shuttering was used to encourage c axis growth. Other papers report the details of the synthesis procedure. The films were characterized using x-ray diffraction (XRD) and transmission electron microscopy (TEM).

Devitrification products of rapidly solidified Ni-Nb amorphous alloys.

1990 ◽  
Vol 48 (4) ◽  
pp. 950-951
Author(s):  
G. A. Bertero ◽  
W.H. Hofmeister ◽  
N.D. Evans ◽  
J.E. Wittig ◽  
R.J. Bayuzick
Keyword(s):  
Electron Microscopy ◽  
Amorphous Structure ◽  
Sulphuric Acid Solution ◽  
X Ray Diffraction ◽  
High Fracture ◽  
Transmission Electron ◽  
Xrd Techniques ◽  
Rapidly Solidified ◽  
Electromagnetically Levitated

Rapid solidification of Ni-Nb alloys promotes the formation of amorphous structure. Preliminary results indicate promising elastic properties and high fracture strength for the metallic glass. Knowledge of the thermal stability of the amorphus alloy and the changes in properties with temperature is therefore of prime importance. In this work rapidly solidified Ni-Nb alloys were analyzed with transmission electron microscopy (TEM) during in-situ heating experiments and after isothermal annealing of bulk samples. Differential thermal analysis (DTA), scanning electron microscopy (SEM) and x-ray diffraction (XRD) techniques were also used to characterize both the solidification and devitrification sequences.Samples of Ni-44 at.% Nb were electromagnetically levitated, melted, and rapidly solidified by splatquenching between two copper chill plates. The resulting samples were 100 to 200 μm thick discs of 2 to 3 cm diameter. TEM specimens were either ion-milled or alternatively electropolished in a methanol-10% sulphuric acid solution at 20 V and −40°C.

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