scholarly journals SYNTHESIS AND STUDY OF THE HETERONUCLEAR ACETYLACETONATE Nd(III) AND Ni(II) COMPLEX AS A PRECURSOR FOR OBTAINING COMPLEX-OXIDE STRUCTURES

2019 ◽  
Vol 85 (8) ◽  
pp. 83-93 ◽  
Author(s):  
Lidia Zheleznova ◽  
Lyudmila Sliusarchuk ◽  
Nadiia Ivakha ◽  
Serhii Kuleshov ◽  
Olena Trunova
Keyword(s):  
Ir Spectroscopy ◽  
Powder Diffraction ◽  
Solid Phase ◽  
Heating Temperature ◽  
Complex Oxide ◽  
Synthesis Methods ◽  
Heterometallic Complex ◽  
X Ray ◽  
Acetylacetonate Complex ◽  
Phase Compound

The heterometallic acetylacetonate complex NdNi(АА)5·6Н2О has been synthesized to obtain nickel-neodymium-containing complex oxide materials. The properties of the complex have been investigated by physico-chemical methods of analysis (elemental analysis, differential thermal analysis, IR spectroscopy, X-ray powder diffraction). The data of X-ray powder diffraction and IR spectroscopy of NdNi(АА)5·6Н2О confirmed the formation of a new heterometallic single-phase compound. In the IR spectrum of NdNi(АА)5·6Н2О, a change is observed in the amount and position of the bands in the region of stretching vibrations of the М-О, CС, CО bonds, as compared to the IR spectra of the monometallic complexes Ni(AA)2·2Н2О and Nd(AA)3·3Н2О. An assessment of the thermal stability of the complex has been performed. It was shown that the synthesized heterometallic complex NdNi(АА)5·6Н2О is thermally more stable than monometallic acetylacetonates of Ni(II) and Nd(III). The heterocomplex can be used as a precursor to obtain heterometallic oxide structures. The pyrolysis of the NdNi(АА)5·6Н2О complex and, for comparison, the pyrolysis of the monocomplexes Ni(AA)2·2Н2О and Nd(AA)3·3Н2О were carried out with changing the thermolysis conditions — change of heating rate (from 5 °C/min to 20 °C/min), change of the final heating temperature (to 500 °C and to 800 °C), change of the exposure time at the final temperature (from 1 hour to 5 hours). It has been established that a change in the temperature conditions of the pyrolysis process affects the characteristics of the materials obtained (degree of amorphism, phase composition, the presence of impurities). The study of the composition of the pyrolysis products of the heterocomplex and the mixture of monometallic acetylacetonates of Ni(II) and Nd(III), obtained under heating to 800°C and holding at this temperature for 3 hours, showed the formation of a complex oxide Nd2NiO4, as well as other phases NiO, Nd6O11, Nd-Ni-O. However, their amount is noticeably smaller in the case of using a heterocomplex. It is shown that the temperature of heat treatment of the heterometallic complex and the time of its pyrolysis are much less in comparison with solid-phase synthesis methods.

Thermochemische Untersuchungen zu den Systemen SE2O3-SeO2. V. Ytterbiumselenoxide auf dem Schnitt Yb2O3-SeO2/Thermochemical Investigations of Systems RE2O3-SeO2. V. Ytterbium Selenium Oxides on the Line Yb2O3-SeO2

2002 ◽  
Vol 57 (8) ◽  
pp. 868-876 ◽  
Author(s):  
H. Oppermann ◽  
M. Zhang-Preße ◽  
P. Schmidt
Keyword(s):  
Thermal Analysis ◽  
Phase Diagram ◽  
Solid State ◽  
Ir Spectroscopy ◽  
Powder Diffraction ◽  
Solid State Reaction ◽  
Total Pressure ◽  
Pressure Measurements ◽  
Thermodynamical Equilibrium ◽  
X Ray

The pure ternary phases on the line Yb2O3-SeO2 in thermodynamical equilibrium have been synthesized by solid state reaction and characterized using X-ray powder diffraction and IR-spectroscopy. There exist three phases: Yb2SeO5, Yb2Se3O9 and Yb2Se4O11, the last one with a homogeneiety range extending a higher SeO2-content. The thermal decompositions have been determined by total pressure measurements, and the thermodynamical data of the compounds have been derived. The phase diagram and the phase barogram have been established using the results of thermal analysis and total pressure measurements.

Needle-Like Mullite Ceramic Prepared by Sol-Gel Process

2011 ◽  
Vol 233-235 ◽  
pp. 2640-2643 ◽  
Author(s):  
Fu Sheng Song
Keyword(s):  
Powder Diffraction ◽  
Solid Phase ◽  
Raw Materials ◽  
Sol Gel ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Mullite Ceramic ◽  
X Ray ◽  
Sol Gel Process ◽  
Ceramic Blocks

Using tetraethoxysilane, aluminum nitrate and aluminum fluoride as raw materials, the precursor of mullite was prepared by sol-gel process. When the precursor sintered at 1200°C, mullite ceramic was obtained. Differential thermal analysis, X-ray powder diffraction and scanning electron microscope were used to characterize the dried mullite gel and ceramic blocks. The results suggest mullite is synthesized by solid-phase reaction mechanism. X-ray powder diffraction indicates mullite is the main crystals phase in the ceramic specimen. SEM micrograph shows the mullite grains in the shape of short rod with length of 20 um when sintered at 1200 °C for 2 h and the grains grown up to acicular with length of more than 50 um when the treating time under 1200 °C achieved to 4 h.

Synthesis, structure and magnetism of a new ionic pentanuclear iron cluster

2020 ◽  
Vol 76 (7) ◽  
pp. 690-694
Author(s):  
Qianjun Deng ◽  
Jiming Wang ◽  
Guangzhao Li ◽  
Shuhua Zhang
Keyword(s):  
Thermogravimetric Analysis ◽  
Ir Spectroscopy ◽  
Elemental Analysis ◽  
Synthesis Methods ◽  
X Ray Diffraction ◽  
Magnetic Studies ◽  
Iron Cluster ◽  
X Ray ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

A new ionic pentanuclear FeIII cluster, namely, triethylazanium tetrakis(μ2-5-amino-1,2,3,4-tetrazolido)tetrakis(μ3-4-chloro-2-{[(1H-tetrazol-1-id-5-yl)imino]methyl}phenolato)di-μ3-oxido-pentairon(III) acetonitrile monosolvate monohydrate, (C6H16N)[Fe5(C8H4ClN5O)4(CH2N5)4O2]·CH3CN·H2O, was synthesized using microvial synthesis methods and characterized by elemental analysis, FT–IR spectroscopy, single-crystal X-ray diffraction and thermogravimetric analysis. Magnetic studies reveal that the complex displays dominant antiferromagnetic intracluster interactions between the FeIII ions through the μ3-oxide bridges.

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.

Retention of (4,4) Connectivity in the Absence of π…π Interactions in a Cadmium tris-Dicyanamide Compound

2006 ◽  
Vol 59 (2) ◽  
pp. 115 ◽  
Author(s):  
Moumita Biswas ◽  
Stuart R. Batten ◽  
Paul Jensen ◽  
Samiran Mitra
Keyword(s):  
Thermogravimetric Analysis ◽  
Ir Spectroscopy ◽  
Powder Diffraction ◽  
Elemental Analysis ◽  
Octahedral Geometry ◽  
X Ray ◽  
Π Interactions ◽  
X Ray Crystallography ◽  
Extended Sheets

An anionic cadmium tris-dicyanamide compound (Et4N)[Cd(N(CN)2)3]·3/4H2O 1 has been synthesized and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, X-ray powder diffraction, and X-ray crystallography. The anions form extended sheets with retention of (4,4) connectivity in the absence of π···π interactions within the cation layers, and with octahedral geometry about individual CdII ions.

Some aspects of the crystal-chemistry of apatites

1993 ◽  
Vol 57 (389) ◽  
pp. 709-719 ◽  
Author(s):  
Yu Liu ◽  
Paola Comodi
Keyword(s):  
Ir Spectroscopy ◽  
Powder Diffraction ◽  
Sedimentary Rock ◽  
Early Stage ◽  
Alkaline Rock ◽  
Ir Absorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Content ◽  
Absorption Features

AbstractTwenty-four apatite (Ap) samples mainly from carbonatite and alkaline rocks were studied by electron microprobe, IR spectroscopy and X-ray powder diffraction. The crystal structures of six were refined using single crystal X-ray diffraction data to R = 1.7-2.5%. The generally high Si content of Ap from carbonatite and alkaline rock has been related to the presence of characteristic Si-O absorptions in IR spectra. Bands, whose intensities change with Si content, were observed at 520, 650, 930 and 1160 cm-1. The IR absorption features of v3 CO3 mode of Ap from carbonatite are different from those of v3 CO3 mode of Ap from sedimentary rock. This phenomenon is probably due to the different effects of F and OH on the CO3 substitution for PO4. The structural refinements yield more information on the CO3=PO4 substitution, which is now supported also by the geometrical evolution of the tetrahedron with increasing CO3 content: the tetrahedral size decreases and the angle distortion increases with C-content. It is likely that the triangular planar CO3 group is disordered on the four faces of PO43-tetrahedron. It was observed also that Ap from early-stage carbonatite is OH-dominant with considerable LREE, Si, CO3 and negligible Mn, Fe, Mg, K, S and C1 contents. They have high Sr/Mn, Si/S and C/S ratios.

X-ray powder diffraction investigation of new high temperature polymorphs of CaTeO3 and CaTe2O5

2001 ◽  
Vol 16 (4) ◽  
pp. 205-211 ◽  
Author(s):  
S. N. Tripathi ◽  
R. Mishra ◽  
M. D. Mathews ◽  
P. N. Namboodiri
Keyword(s):  
High Temperature ◽  
Powder Diffraction ◽  
Room Temperature ◽  
Solid Phase ◽  
High Temperature Phase ◽  
Unit Cell ◽  
Stable Phase ◽  
Temperature Phase ◽  
X Ray ◽  
Monoclinic Lattice

X-ray powder diffraction investigation of the new high temperature polymorphs beta- and gamma-CaTeO3 and gamma- and delta-CaTe2O5 and picnometric measurements of the room temperature phases of the two compounds have been carried out. The study led to the elucidation of their unit cell structures and assignment of entirely new lattice types and parameters to the room temperature phases of CaTeO3 and CaTe2O5 in contrast and supersession to the existing structural information. The results are as follows: CaTeO3 has only one stable phase at room temperature and temperatures up to 882 °C, i.e., α- and has a triclinic unit cell with a=4.132±0.003 Å, b=6.120±0.006 Å, c=12.836±0.013 Å, α=121.80°, β=99.72°, γ=97.26°. The first high temperature phase stable between 882 and 894 °C, i.e., β-CaTeO3, has a monoclinic lattice: a=20.577±0.007 Å, b=21.857±0.009 Å, c=4.111±0.002 Å, β=96.15°, while the next phase stable above 894 °C, i.e., γ-CaTeO3, has a hexagonal unit cell with parameters: a=14.015±0.0001 Å, c=9.783±0.001 Å, c/a=0.698. CaTe2O5 has one stable phase at temperatures up to 802 °C, i.e., α-CaTe2O5 with a monoclinic lattice and parameters: a=9.069±0.002 Å, b=25.175±0.007 Å, c=3.366±0.001 Å, β=98.29 °. The first high temperature phase stable in the range 802–845°, i.e., β-CaTe2O5, is monoclinic with unit cell parameters: a=4.146±0.001 Å, b=5.334±0.002 Å, c=6.105±0.002 Å, β=98.362 °; the next higher temperature phase stable over 845–857 °C, i.e., γ-CaTe2O5, has an orthorhombic unit cell with: a=8.638±0.001 Å, b=9.291±0.001 Å, c=7.862±0.001 Å and the highest temperature solid phase stable above 857 °C, i.e., δ-CaTe2O5 has a tetragonal unit cell with a=5.764±0.000 Å, c=32.074±0.020 Å, c/a=5.5637.

scholarly journals USE OF DUST X-RAY DIFFRACTION IN THE CHARACTERIZATION OF PEROVSKITAS TYPE FERRITES

2008 ◽  
Vol 05 (9) ◽  
pp. 23-30
Author(s):  
Márcio DE PAULA ◽  
Regina Helena Porto FRANCISCO
Keyword(s):  
Solid State ◽  
Powder Diffraction ◽  
Structural Changes ◽  
Solid Phase ◽  
Orthorhombic Phase ◽  
Polycrystalline Sample ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
X Ray

The X-ray diffraction is one experimental method very important on characterization solids compounds. In the case of polycrystalline samples, the x-ray powder diffraction allows for the identification of the solid phase and the characterization of structural changes. The present paper was prepared any antiferromagnetic ceramic phases, bicalcic ferrite derivate (Ca2Fe2O5) by solid state reaction from pulverized reagents and mixed manually. These were heated in the Pt melting pan, in air oven at temperature between 1000 and 1450oC for 12h. The occurrence of reaction with reagents and the products obtained were identified and structurally characterized by X-ray diffraction by polycrystalline sample. Mixtures of regents CaCO3, SrCO3, BaCO3, Fe2O3, Nb2O5, Have been made with various symmetries: a) Ba2Fe2O5, b) CaBaFe2O5, c) Ba2FeNbO6, d) Ca2Fe2O5, (e) Ba2Nb2O7, (f) Ca2Nb2O7, (g) Sr2Nb2O7, (h) CaBaFeNbO6. The products obtained showed that O2 of the air participated of reactions by providing the anions oxides required for obtaining the cubic phase. The formation of this phase was also helped by the presence of barium and niobium, since in the absence of these elements, can be seen the formation of orthorhombic phase, characteristic of Ca2Fe2O5.

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