X-Ray and Thermogravimetric Analyzes of Mechanically Activated Nickel Ferrites

2019 ◽  
Vol 970 ◽  
pp. 17-23
Author(s):  
Alexandr Astafyev ◽  
Evgeniy Nikolaev ◽  
Elena Lysenko ◽  
Anatoly P. Surzhikov
Keyword(s):  
Mechanical Activation ◽  
Phase Analysis ◽  
Nickel Ferrite ◽  
Solid Phase ◽  
Initial Mixture ◽  
Thermal Gravimetric ◽  
Phase Synthesis ◽  
X Ray ◽  
Activation Rate ◽  
Applied External Magnetic Field

This article shows a study of the effect of mechanical activation of the initial mixture of reagents NiO and Fe2O3 at different speeds of grinding bowl rotation on synthesis of nickel ferrite. Nickel ferrite was produced by the solid-phase synthesis at a temperature of 900 °C for 240 minutes. The obtained ferrite samples were investigated by thermal gravimetric and X-ray phase analysis. The Curie temperature values are obtained, as well as the magnitude of the change of detected instrument weight at the magnetic phase transition (ferromagnetic-paramagnetic) of nickel ferrite using thermal gravimetric curves (TG/DTG) with applied external magnetic field. Increasing of the homogeneity degree of ferrite materials with an increase in the mechanical activation rate is shown based on the data of X-ray phase analysis. The experimental results obtained from thermal, magnetic, and X-ray analyzes were compared.

scholarly journals Solid-phase synthesis of ytterbium zirconate using mechanical activation

2021 ◽  
Vol 12 (2-2021) ◽  
pp. 154-158
Author(s):  
O. A Kuzmenkov ◽  
◽  
A. M. Kalinkin ◽  
Keyword(s):  
Mechanical Activation ◽  
Solid Phase ◽  
Planetary Mill ◽  
Phase Method ◽  
Stoichiometric Mixture ◽  
Phase Synthesis ◽  
X Ray ◽  
Zirconium Oxides ◽  
Solid Phase Method ◽  
Complex Thermal Analysis

Nanocrystalline ytterbium zirconate Yb4Zr3O12 was prepared by the solid-phase method using mechanical activation of stoichiometric mixture of zirconium and ytterbium oxides. Mechanical activation was carried out in an AGO-2 centrifugal-planetary mill at a centrifugal factor of 40 g for 10 min. The processes occurring during the calcination of the mechanically activated mixture of ytterbium and zirconium oxides in the range from 600 to 1300 °C were investigated using X-ray phase analysis, IR spectroscopy, and complex thermal analysis.

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.

Study of Mechanical Activation Processes of Mica Bearing Rocks

2014 ◽  
Vol 1040 ◽  
pp. 367-371 ◽  
Author(s):  
Valeriy M. Pogrebenkov ◽  
Kirill S. Kostikov ◽  
Yu.P. Azhel ◽  
K.S. Kamyshnaya
Keyword(s):  
Mechanical Activation ◽  
Phase Analysis ◽  
Mechanical Treatment ◽  
Time Intervals ◽  
Treatment Methods ◽  
X Ray ◽  
Study Results ◽  
Muscovite Mica

The study results of mica bearing rocks from the Mamskoye and Kuletskoye deposits and the processes, involved in grinding and activating muscovite mica from the rocks using a ball and a planetary mills, a disintegrator and a pneumoimpulsive installation depending on different time intervals and other grinding factors, are presented in this paper. The resultant materials were examined by the methods of X-ray phase analysis, derivatography, microscopy and others, which resulted in drawing the conclusions concerning the applicability of different mechanical treatment methods applied in obtaining ground mica for various uses.

scholarly journals Hydrate of 2,3:4,5-di-O-isopropylidene-β-D-arabino-hexos-2-ulo-2,6-pyranose as new crystalline reagent in the preparation of Amadori derived peptides

2010 ◽  
Vol 8 (1) ◽  
pp. 28-33 ◽  
Author(s):  
Piotr Stefanowicz ◽  
Joanna Batorska ◽  
Monika Kijewska ◽  
Hubert Bartosz-Bechowski ◽  
Zbigniew Szewczuk ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Nmr Spectroscopy ◽  
High Resolution ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Crystalline Hydrate ◽  
Phase Synthesis ◽  
X Ray ◽  
Independent Molecules ◽  
Stable Reagent

AbstractWe established, that crystalline hydrate of 2,3:4,5-di-O-isopropylidene-β-D-arabino-hexos-2-ulo-2,6-pyranose is a new, convenient and stable reagent for solid phase synthesis of peptide derived Amadori products. The structure of the title compound was studied by X-ray analysis, NMR spectroscopy, and high resolution ESI-MS. The crystal structure indicated the existence of two symmetry-independent molecules that were not connected with hydrogen bonds. A comparison with previously reported 2,3:4,5-di-O-isopropylidene-β-D-fructopyranose revealed, that these two compounds are isostructural.

scholarly journals Структура и термодинамические свойства SmGaGe-=SUB=-2-=/SUB=-O-=SUB=-7-=/SUB=-

2020 ◽  
Vol 62 (2) ◽  
pp. 332
Author(s):  
Л.Т. Денисова ◽  
М.С. Молокеев ◽  
Л.А. Иртюго ◽  
В.В. Белецкий ◽  
Н.В. Белоусова ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Heat Capacity ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Phase Synthesis ◽  
High Temperature Heat Capacity ◽  
X Ray ◽  
Temperature Heat

SmGaGe2O7 has been prepared by solid-phase synthesis in air at temperatures from 1273 to 1473 K using the Sm2O3, Ga2O3, and GeO2 oxides as starting materials. The structure of the studied germanate was determined by X-ray diffraction (space group P2_1 / c; a = 7.18610(9) Angstrem, b = 6.57935(8) Angstrem, c = 12.7932(2) Angstrem). Its high-temperature heat capacity has been measured by differential scanning calorimetry. The obtained experimental dependence C_p = f (T) has been used to evaluate the thermodynamic properties of the compound.

Solid-Phase Formation of Li-Zn Ferrite under High-Energy Impact

2019 ◽  
Vol 970 ◽  
pp. 250-256
Author(s):  
Evgeniy Nikolaev ◽  
Elena Lysenko ◽  
Anatoly P. Surzhikov
Keyword(s):  
Phase Composition ◽  
Powder Diffraction ◽  
Zinc Ferrite ◽  
Solid Phase ◽  
Initial Mixture ◽  
High Energy ◽  
Ceramic Technology ◽  
Thermal Synthesis ◽  
X Ray ◽  
Zn Ferrite

The effect of complex high-energy action, including mechanical milling of Li2CO3-Fe2O3-ZnO initial reagents mixture and its consistent heating by the pulsed electron beam on solid-phase synthesis was studied by X-ray powder diffraction and thermal analyses. The initial mixture Li2CO3-Fe2O3-ZnO corresponds to the ferrite with stoichiometric formula: Li0.5(1–x)ZnxFe2.5–0.5xО4, where х = 0.2. The same studies were carried out with thermal heating in a laboratory furnace for detection the effect of radiation on the formation of phase composition lithium-zinc ferrite. Initial mixture was milled in AGO-2S planetary ball mill with a milling speed of 2220 rpm for 60 min. Radiation-thermal synthesis of the milled mixture was carried out by the pulsed electron accelerator (ILU-6) at 600°C and 750°C. The maximum time of the isothermal stage was 60 minutes. According to the X-ray powder diffraction and thermogravimetric analysis, it was found that the complex high-energy action leads to decrease a temperature and time of obtaining lithium-zinc ferrite homogeneous in phase composition. The proposed high-energy regimes allow to synthesized lithium-zinc ferrites at 600 °C for 60 minutes, which is much lower compared to conventional ceramic technology.

scholarly journals Acylation of Lignin with Different Acylating Agents by Mechanical Activation-Assisted Solid Phase Synthesis: Preparation and Properties

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 907 ◽  
Author(s):  
Xiaohong Zhao ◽  
Yanjuan Zhang ◽  
Mei Yang ◽  
Zuqiang Huang ◽  
Huayu Hu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Mechanical Activation ◽  
Chain Length ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Carbon Number ◽  
Carbon Chain Length ◽  
Hydroxyl Groups ◽  
Phase Synthesis ◽  
Cyclic Anhydrides

Acylated lignins with substituents consisting of different lengths of carbon chains were prepared by a mechanical activation-assisted solid phase synthesis (MASPS) technology with a customized stirring ball mill as a reactor. The structures and properties were analyzed by UV/Vis, FTIR, NMR, SEM, DSC, and TG. The results showed that the acylated lignins were successfully prepared with either non-cyclic or cyclic anhydrides as the acylating agents. Both aliphatic hydroxyl and phenolic hydroxyl groups of lignin reacted with non-cyclic anhydrides, and different reactivity of acylating agents resulted in different relative contents of phenolic and aliphatic substituents in the products. The reactivity of the cyclic anhydrides was weaker than that of the non-cyclic anhydrides, and the reactivity of the acylating agents decreased with increasing carbon chain length and unsaturated bonds of acyl groups. All of the acylated lignins except maleylated lignin had a lower glass transition temperature (Tg) than the original lignin. The acylated lignins prepared with non-cyclic anhydrides had better thermal stability than original lignin, and the thermal stability increased, but Tg decreased with an increasing chain length of the acyl groups. The acylated lignins prepared with cyclic anhydrides had higher a Tg than those with non-cyclic anhydrides with the same carbon number, and the thermal stability was not obviously improved.

Thermal Stability of Aluminum Titanate Ceramics

2016 ◽  
Vol 680 ◽  
pp. 137-140 ◽  
Author(s):  
Hai Jian Li ◽  
Xiao Shuang Shao ◽  
Kai Li ◽  
Zhen Hua Geng ◽  
Ping Wu
Keyword(s):  
Thermal Stability ◽  
Solid Phase ◽  
Synthesis Method ◽  
Electron Back Scatter Diffraction ◽  
Aluminum Titanate ◽  
X Ray Diffraction ◽  
Phase Synthesis ◽  
X Ray ◽  
Titanate Ceramics ◽  
Thermal Stability Of

The thermal stability of aluminum titanate (AT) ceramics is the main problem that restricted its extensive applications in many fields. In this paper, AT ceramics doped with single or composite additives of MgO, SiO2, mullite were fabricated by solid phase synthesis method. The thermal stability was tested by heated for 50h at 1100°C, and the phases of the samples were tested by X-ray diffraction (XRD) , and the microstructure were tested by SEM. The mechanism of the thermal stability of AT with additive was discussed based on DSC/TGA and electron back scatter diffraction pattern (EBSP). The results show that the adding of composite additives can improve the thermal stability of AT ceramics.

Solid-Phase Synthesis of KNaSO4 in a Thermal X-Ray Machine Followed by a Study of the Synthesis Product during Cooling

2021 ◽  
Vol 47 (2) ◽  
pp. 181-185
Author(s):  
O. Yu. Shorets ◽  
S. K. Filatov ◽  
V. A. Firsova ◽  
R. S. Bubnova
Keyword(s):  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Synthesis Product ◽  
Phase Synthesis ◽  
X Ray
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