scholarly journals Structural and Magnetic Рroperties of Copper Substituted Mg-Ferrites

2018 ◽  
Vol 185 ◽  
pp. 04010
Author(s):  
Tatiana Kiseleva ◽  
Vladislav Kabanov ◽  
Alexander Ilyushin ◽  
Gennadiy Markov ◽  
Deleg Sanga ◽  
...  
Keyword(s):  
Saturation Magnetization ◽  
Heat Generation ◽  
Magnetic State ◽  
Ceramic Technology ◽  
Ferrite Powder ◽  
Polycrystalline Ferrite ◽  
X Ray ◽  
Cu Substitution ◽  
Phase Crystal ◽  
Ion Substitution

Polycrystalline ferrite powders of Mg1-xCuxFe2O4 (x = 0.2, 0.4, 0.6, 0.8, 1) system synthesized by ceramic technology have been investigated. Samples showed the non-monotonic dependency of heat generation effect in AC magnetic field with increasing concentration of copper. To reveal peculiarities of the structural and magnetic state of the samples and their influence on the heat generation ability we performed a complex study, including X-ray diffractometry, Mössbauer spectroscopy, Scanning electron microscopy, measurements of temperature dependencies of susceptibility and saturation magnetization, hysteresis parameters and FORC. Typical ferrimagnetic character with small coercivity and saturation magnetization was found. We carried out that anomalous influence of Cu2+ ion substitution respectively to the Mg1-xCuxFe2O4 ferrite powder manifested in heat generation ability rise up to x=0.6. The subsequent sharp reducing of this characteristic were accompanied by the main phase crystal structure distortion followed by phase separation to cubic and tetragonal structure. This was matched by in an increase of ferrite particles crystallite size and size distribution appearance. The saturation magnetization and Curie temperature dependencies observed for powders via Cu substitution was explained by phase composition, the cations distributions between ferrite sublattices, modulation of exchange interaction.

scholarly journals X-ray photoelectron spectra of iron-sulphur proteins

1975 ◽  
Vol 149 (2) ◽  
pp. 471-474 ◽  
Author(s):  
P T Andrews ◽  
C E Johnson ◽  
B Wallbank ◽  
R Cammack ◽  
D O Hall ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Magnetic State ◽  
High Potential ◽  
Spin Coupling ◽  
Photoelectron Spectra ◽  
Clostridium Pasteurianum ◽  
Active Centre ◽  
Core Polarization ◽  
X Ray ◽  
Polarization Splitting

The X-ray photoelectron spectra of the 2p, 3s and 3p levels of iron in oxidized Clostridium pasteurianum ferredoxin indicate that the eight iron atoms in the molecule are indistinguishable. Their magnetic state is indicated both by core polarization splitting of the 3s electrons, and by ‘shake-up’ satellites on the 2p lines. Similar satellites are observed in the 2p lines of reduced Chromatium high-potential iron-sulphur proteins and oxidized spinach ferredoxin, indicating that there too the iron atoms are magnetic. The low observed magnetic susceptibility of these proteins is therefore due to spin-coupling between the iron atoms in the active centre.

Development of 3D Printing Technology with Ceramic Paste and Study of Properties of Printed Corundum Products

2021 ◽  
Vol 1040 ◽  
pp. 178-184
Author(s):  
Andrey S. Dolgin ◽  
Aleksei I. Makogon ◽  
Sergey P. Bogdanov
Keyword(s):  
3D Printing ◽  
Aluminum Oxide ◽  
Reference Sample ◽  
Physical And Mechanical Properties ◽  
Ceramic Technology ◽  
Raw Material ◽  
Energy Costs ◽  
Additive Technology ◽  
X Ray ◽  
Manufacturing Time

Today 3D printing with ceramics is a promising direction in the development of additive technologies. In this work, we have developed a technology for printing with ceramic pastes based on aluminum oxide and wax, namely: an extruder for printing with ceramic pastes was modeled and manufactured, the composition of the slip was selected and the paste for printing was made. After choosing the print parameters, test samples were printed: a disk and a box. Since 3D printing with ceramics is just one of the stages of manufacturing ceramic products, then we selected the parameters for drying and sintering the raw material. Drying of products is necessary to burn off an excess amount of a binder (paraffin), and due to sintering; the raw material acquires final strength and mechanical characteristics. After sintering, the sintering parameters and physical and mechanical properties of the products were measured. The microstructure of the printed products was studied using scanning electron microscopy. The phase change during sintering was studied by X-ray analysis. All obtained properties were compared with a reference sample (corundum tile made of aluminum oxide of the same grade, but using traditional ceramic technology, including pressing, drying and sintering of the product). In terms of all properties, the printed ceramics are not significantly inferior to the reference sample; however, in general, the additive technology has more advantages, such as a wide variety of shapes, shorter manufacturing time for parts, and lower energy costs.

scholarly journals Ferromagnetic Properties of N-Doped and Undoped TiO2 Rutile Single-Crystal Wafers with Addition of Tungsten Trioxide

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1934 ◽  
Author(s):  
Jing Xu ◽  
Haiying Wang ◽  
Zhongpo Zhou ◽  
Zhaorui Zou
Keyword(s):  
Magnetic Properties ◽  
Single Crystal ◽  
Saturation Magnetization ◽  
Photoelectron Spectroscopy ◽  
Oxygen Vacancies ◽  
Tio2 Surface ◽  
Doped Tio2 ◽  
X Ray ◽  
N Doping ◽  
Tio2 Rutile

In this work, undoped, N-doped, WO3-loaded undoped, and WO3-loaded with N-doped TiO2 rutile single-crystal wafers were fabricated by direct current (DC) magnetron sputtering. N-doping into TiO2 and WO3 loading onto TiO2 surface were used to increase and decrease oxygen vacancies. Various measurements were conducted to analyze the structural and magnetic properties of the samples. X-ray diffraction results showed that the N-doping and WO3 loading did not change the phase of all samples. X-ray photoelectron spectroscopy results revealed that W element loaded onto rutile single-crystal wafers existed in the form of WO3. UV-Vis spectrometer results showed that the absorption edge of WO3-loaded undoped and WO3-loaded with N-doped TiO2 rutile single-crystal wafers had red shift, resulting in a slight decrease in the corresponding band gap. Photoluminescence spectra indicated that oxygen vacancies existed in all samples due to the postannealing atmosphere, and oxygen vacancies density increased with N-doping, while decreasing with WO3 loading onto TiO2 surface. The magnetic properties of the samples were investigated, and the saturation magnetization values were in the order N-doped > WO3-loaded with N-doped > undoped > WO3-loaded undoped rutile single-crystal wafers, which was the same order as the oxygen vacancy densities of these samples. N-doping improved the saturation magnetization values, while WO3-loaded decreased the saturation magnetization values. This paper reveals that the magnetic properties of WO3-loaded with N-doped rutile single-crystal wafers originate from oxygen vacancies.

scholarly journals NDE Development for Ceramics for Advanced Heat Engines

1991 ◽  
Author(s):  
R. W. McClung ◽  
D. R. Johnson
Keyword(s):  
Computed Tomography ◽  
Process Development ◽  
Low Voltage ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Ceramic Technology ◽  
X Ray ◽  
Oak Ridge ◽  
Heat Engines ◽  
X Ray Computed

Following an assessment of needs for NDT and characterization of ceramics for the DOE program, Ceramic Technology for Advanced Heat Engines (CTAHE), many NDT projects have been implemented under the sponsorship of CTAHE to address the needs. Tasks at Argonne National Laboratory have involved X-ray computed tomography and nuclear magnetic resonance imaging. The Oak Ridge National Laboratory has emphasized high-frequency ultrasonics, low-voltage radiography, and an advanced system for X-ray computed tomography. A brief investigation was made by Radiation Sciences, Inc., into the feasibility of synchrotron-computed tomography for ceramics. New programs recently initiated at Allison and Garrett integrate ultrasonics, radiography, and other methods into a major effort on life prediction. New programs at Norton and GTE on advanced processing of ceramics also place heavy emphasis on several methods of NDT for process development and control. Initial work on NDT standards has begun in ASTM Committees E-7 and C-28.

scholarly journals Effect of the electrodeposition potential on the magnetic properties of FeCoNi films

2019 ◽  
Vol 37 (3) ◽  
pp. 389-394
Author(s):  
Setia Budi ◽  
Sukro Muhab ◽  
Agung Purwanto ◽  
Budhy Kurniawan ◽  
Azwar Manaf
Keyword(s):  
Magnetic Properties ◽  
Saturation Magnetization ◽  
Sulfate Solution ◽  
Synthesis Process ◽  
Magnetic Characteristics ◽  
Soft Magnetic ◽  
X Ray ◽  
Ni Content ◽  
The Mean ◽  
Feconi Alloy

AbstractThe effect of electrodeposition potential on the magnetic properties of the FeCoNi films has been reported in this paper. The FeCoNi electrodeposition was carried out from sulfate solution using potentiostatic technique. The obtained FeCoNi films were characterized by X-ray diffractometer (XRD), atomic absorption spectrometer (AAS) and vibrating sample magnetometer (VSM). It has been shown that the electrodeposition potential applied during the synthesis process determines the magnetic characteristics of FeCoNi films. The more negative potential is applied, the higher Ni content is in the FeCoNi alloy. At the same time, Co and Fe showed almost similar trend in which the content decreased with an increase in applied potential. The mean crystallite size of FeCoNi films was ranging from 11 nm to 15 nm. VSM evaluation indicated that the FeCoNi film is a ferromagnetic alloy with magnetic anisotropy. The high saturation magnetization of FeCoNi film was ranging from 86 A·m2/kg to 105 A·m2/kg. The film is a soft magnetic material which was revealed by a very low coercivity value in the range of 1.3 kA/m to 3.7 kA/m. Both the saturation magnetization and coercivity values decreased at a more negative electrodeposition potential.

Magnetic and Optical Properties of Eu-doped GaN

2006 ◽  
Vol 955 ◽  
Author(s):  
Jennifer Hite ◽  
G T Thaler ◽  
J H Park ◽  
A J Steckl ◽  
C R Abernathy ◽  
...  
Keyword(s):  
Saturation Magnetization ◽  
Room Temperature Ferromagnetism ◽  
Inverse Correlation ◽  
Absolute Intensity ◽  
Growth Conditions ◽  
X Ray Diffraction ◽  
Cell Temperature ◽  
X Ray ◽  
Pl Intensity ◽  
The Eu

ABSTRACTGaN films were doped with Eu to a concentration of ∼0.12 at. % during growth at 800°C by molecular beam epitaxy, with the Eu cell temperature held constant at 470°C. All samples were post-annealed at 675°C. The films exhibited strong photoluminescence (PL) in the red (622 nm) whose absolute intensity was a function of the Ga flux during growth, which ranged from 3-5.4×10−7 Torr. The maximum PL intensity was obtained at a Ga flux of 3.6×10−7 Torr. The samples showed room temperature ferromagnetism with saturation magnetization of ∼0.1-0.45 emu/cm3, consistent with past reports where the Eu was found to be predominantly occupying substitutional Ga sites. There was an inverse correlation between the PL intensity and the saturation magnetization in the films. X-ray diffraction showed the presence of EuGa phases under all of our growth conditions but these cannot account for the observed magnetic properties.

THE GIANT MAGNETOSTRICTION OF [Fe/Tb/Fe/Dy]n MULTILAYER FILMS UNDER DIFFERENT ANNEALING TEMPERATURE

2009 ◽  
Vol 16 (01) ◽  
pp. 123-126 ◽  
Author(s):  
X. D. LI ◽  
Z. J. ZHAO ◽  
T. FENG ◽  
L. K. PAN ◽  
S. M. HUANG ◽  
...  
Keyword(s):  
Saturation Magnetization ◽  
Annealing Temperature ◽  
Multilayer Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Low Field ◽  
Giant Magnetostriction

The effect of annealing temperature on the magnetic and giant magnetostriction (GMS) of [ Fe / Tb / Fe / Dy ]n multilayer films were investigated. X-ray diffraction showed that the multilayer films' microstructures were still in amorphous at annealing temperature 300°C. The multilayer films began to crystalline at annealing temperature 400°C. The saturation magnetization of multilayer films increased by the increasing annealed temperature. The coercivity first decreased at annealing temperature 300°C and then increased when the annealing temperature was higher than 400°C. The multilayer films had good low-field GMS, and the magnetostriction of the multilayer films increased by the increasing annealing temperature.

Synthesis and properties of double gadolinium tellurites

2021 ◽  
Vol 103 (3) ◽  
pp. 67-73
Author(s):  
A.A. Toibek ◽  
◽  
K.T. Rustembekov ◽  
D.A. Kaikenov ◽  
M. Stoev ◽  
...  
Keyword(s):  
Phase Analysis ◽  
Solid Phase ◽  
Heat Capacities ◽  
Ceramic Technology ◽  
Phase Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Temperature Range ◽  
Diffraction Patterns

For the first time, double gadolinium tellurites of the composition GdMIITeO4.5 (MII — Sr, Ba) were synthesized by the solid-phase method. The solid-phase synthesis of samples was carried out from decrepitated gadolinium (III) and tellurium (IV) oxides, strontium, and barium carbonates according to the standard ceramic technology. The synthesis was carried out in the temperature range of 800-1100 °C. The samples obtained were confirmed by X-ray phase analysis. X-ray phase analysis was carried out on an Empyrean instrument in the XRDML Pananalitical format. The intensity of the diffraction maxima was estimated on a 100-point scale. X-ray diffraction patterns indexing of the powder of gadolinium tellurites — alkaline earth metals studied were carried out by the homology method. The reliability and correctness of the results of indexing the X-ray diffraction patterns are confirmed by the good agreement between the experimental and calculated values of the interplanar distances (d) and the agreement between the values of the X-ray and pycnometric densities. It was found that compounds GdSrTeO4.5 and GdBaTeO4.5 crystallize in the monoclinic system and have the unit cell parameters, namely GdSrTeO4.5 — a = 12.7610, b = 10.4289, c = 8.6235 Å, V° = 1141.83 Å3, β = 95.77°, Z = 5, ρrent. = 3.22, ρpikn. = (3.10±0.09) g/cm3; GdBaTeO4.5 — a = 15.7272, b = 15.8351, c = 7.1393 Å, V° = 1769.72 Å3, β = 95.53°, Z = 8, ρrent = 3.71, ρpick = (3.61±0.10) g/cm3. Using the Landiya method, the standard heat capacities of the compounds were estimated from the calculated values of the standard entropies, and the temperature dependences of the heat capacities of the gadolinium tellurites synthesized were determined in the temperature range of 298–850 K.

Hierarchical structure of the triclinic α-phase crystal in nylon 6,12 mediated by two-dimensional confinement

2020 ◽  
Vol 53 (1) ◽  
pp. 27-33
Author(s):  
Ziwei Lai ◽  
Shuailin Zhang ◽  
Nan Zheng ◽  
Shichen Yu ◽  
Masaki Ageishi ◽  
...  
Keyword(s):  
Hierarchical Structure ◽  
Phase Cell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hierarchical Nanostructure ◽  
Α Phase ◽  
Triclinic Symmetry ◽  
Phase Crystal ◽  
Unit Cells ◽  
The Impact

It has been recognized that macromolecular chains can self-assemble into a hierarchical structure from lamellae to spherulites in bulk crystallization. However, little account has been taken of crystal symmetry effects on the hierarchical nanostructure in polymers under cylindrical confinement. In this research, a model polymer, nylon 6,12, most commonly occurring in the triclinic α phase, was chosen in order to demonstrate the effect of triclinic symmetry on the 2D-constrained polymer nanostructure. The self-arranging unit of nylon 6,12 takes various forms, including stems, unit cells, hydrogen-bonded sheets, lamellae and complex spherulites, which is an essential structural feature for investigating hierarchical nanostructure. The rod nanostructure in confinement was examined by cross-checking electron and X-ray diffraction techniques. It is found that the a* axis of the α-phase cell is inclined at about ±6–11° to the rod long axis within the a*b* plane around the c axis (c axis ⊥ rod long axis). The rotation of the a*b* plane most likely results from the impact of the triclinic symmetry on the molecular chain packing under 2D confinement. A mechanism for this a*b* plane tilting is proposed.

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