scholarly journals Кристаллохимия и магнитные свойства гексаферрита BaFe-=SUB=-12-=/SUB=-O-=SUB=-19-=/SUB=- при гетеровалентном замещении железа цирконием

2022 ◽  
Vol 64 (2) ◽  
pp. 179
Author(s):  
В.Г. Костишин ◽  
В.В. Коровушкин ◽  
И.М. Исаев ◽  
Д.В. Салогуб ◽  
С.В. Труханов ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Phase Composition ◽  
Chemical Composition ◽  
Barium Hexaferrite ◽  
Impurity Phase ◽  
Isomorphic Substitution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxygen Coordination ◽  
Heterovalent Isomorphism

Samples of BaFe12O19 M-type barium hexaferrite with partial iron substitution by zirconium ions (concentration up to 10 at.%) have been synthesized and investigated. Studies of crystal features, phase composition, and magnetic properties were carried out using X-ray diffraction, Mössbauer spectroscopy, and VSM respectively. The presence of limited heterovalent isomorphism by the 2Fe3+ → Zr4+ + Fe2+ mechanism was shown. The limit of heterovalent isomorphic substitution by zirconium ions in barium hexaferrite (x = 0.6) was established. It was noted that additional sextets in the Mössbauer spectra of barium hexaferrite can be formed during the localization of Zr4+ ions predominantly in the 12k and 4f2 positions due to the frustration of the magnetic structure. The correlation between the chemical composition (concentration of zirconium ions), impurity phase formation, the peculiarities of the distribution of substituents over oxygen coordination, and the magnetic properties was established.

scholarly journals Determination of Chromite Sands Suitability for Use in Moulding Sands

2017 ◽  
Vol 17 (2) ◽  
pp. 107-110
Author(s):  
K. Stec ◽  
J. Podwórny ◽  
B. Psiuk ◽  
Ł. Kozakiewicz
Keyword(s):  
Phase Composition ◽  
High Temperature ◽  
Chemical Composition ◽  
Chemical Properties ◽  
Grinding Process ◽  
X Ray Diffraction ◽  
Scanning Microscope ◽  
Spectroscopy Technique ◽  
X Ray

Abstract Using the available analytical methods, including the determination of chemical composition using wavelength-dispersive X-ray fluorescent spectroscopy technique and phase composition determined using X-ray diffraction, microstructural observations in a highresolution scanning microscope equipped with an X-ray microanalysis system as well as determination of characteristic softening and sintering temperatures using high-temperature microscope, the properties of particular chromite sands were defined. For the study has been typed reference sand with chemical properties, physical and thermal, treated as standard, and the sands of the regeneration process and the grinding process. Using these kinds of sand in foundries resulted in the occurrence of the phenomenon of the molding mass sintering. Impurities were identified and causes of sintering of a moulding sand based on chromite sand were characterized. Next, research methods enabling a quick evaluation of chromite sand suitability for use in the preparation of moulding sands were selected.

IMPROVED MAGNETIC PROPERTIES OF Sm COMBINING Co OR/AND Zn SUBSTITUTED BARIUM M-TYPE HEXAFERRITES

2012 ◽  
Vol 26 (26) ◽  
pp. 1250141 ◽  
Author(s):  
Y. B. HAN ◽  
J. SHA ◽  
L. N. SUN ◽  
Q. TANG ◽  
Q. LU ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Phase Composition ◽  
Magnetocrystalline Anisotropy ◽  
Sol Gel ◽  
Combustion Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Barium Hexaferrites ◽  
Auto Combustion ◽  
Magnetic Dilution

Sm (Co or/and Zn) substituted nanocrystalline barium hexaferrites were synthesized by the sol–gel auto-combustion process, then X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) were used to characterize and discuss the phase composition and the magnetic properties of the as-prepared barium hexaferrites. All results showed that the phase composition and magnetic properties were closely related to the doping elements and x. Owing to hyperfine field, canting spin, magnetic dilution and impurity phases, the saturation magnetization (Ms) of all samples increased firstly, and then decreased. Considering the crystallization, the magnetocrystalline anisotropy and the ions occupancy, the doping elements and x critically affected the coercivity (Hc). Compared the magnetic properties of all the samples, it is concluded that Zn 2+ and Co 2+ influenced each other and Zn 2+ occupied 4f2 sites prior to Co 2+, which led to the increase of Ms and the decrease of Hc.

scholarly journals Long Time Stability Investigation for Structural and Magnetic Properties of Ti-doped Barium Ferrite

2019 ◽  
Vol 3 (2) ◽  
pp. 53-57
Author(s):  
Mohammed Abdul Malek Al Saadi
Keyword(s):  
Magnetic Properties ◽  
Room Temperature ◽  
Structural Characteristics ◽  
Barium Hexaferrite ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Storage Process ◽  
X Ray ◽  
Air Atmosphere ◽  
Long Time

Barium hexaferrite (BHF) (BaFe12O19) and its substituted derivatives have been considered as the most potential magnetic candidates with considerable chemical stability and physiochemical characteristics. BHF with x ferrite ions substituted by titanium (Ti-doped BTHF) (BaTixFe12-xO19) (x=1 and x=3) was prepared from ferric oxide (Fe2O3), barium oxide (BaO), and titanium oxide (TiO2) of purity >98%. The materials were mixed with deionized water and then dried at 1100°C and 1200°C overnight. For the formation of BaFe12O19 phase, the mixture was annealed at a rate of 10°C/min in static air atmosphere until reaching 1200°C and then maintained for 10 h. Structural properties of these samples were measured using X-ray diffraction (XRD) and scanning electron microscopy, while magnetic properties were measured using vibrating sample magnetometer (VSM) device. Magnetic and structural characteristics are investigated after preserving Ti-doped BHF samples at room temperature and ambient conditions for 12 years. The samples are characterized using the same previous techniques to find out the possible effect of long period storage on their properties. The results showed that the storage process has little effect on these properties where the granular size increased due to increased oxidation. XRD tests also showed the absence of Ti at low ratios due to increased oxidation of ferrite. VSM results showed increased magnetic properties after storage due to increased iron oxide.

Spinel Structured Iron Gallium Oxynitride - Fe2GaO2N2

2021 ◽  
Vol 1160 ◽  
pp. 45-50
Author(s):  
Savitha Kadencheri Unnikrishnan
Keyword(s):  
Magnetic Properties ◽  
Chemical Composition ◽  
Spinel Structure ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
R Factor ◽  
Novel Material ◽  
Optical And Magnetic Properties ◽  
Co Precipitation

A facile method was successfully developed to prepare Ternary oxynitride of iron and gallium. Initially mixed oxyhydroxides of Iron and gallium were prepared by co-precipitation method. Then this was nitrided using urea and agar in presence of ammonia at 900°C, which gave mixed cation oxynitride . This mixed oxynitride was characterized using XRD, XPS and SEM. The X-ray diffraction pattern of the Fex’GaxOyNz phase was refined within the cubic spinel structure (space group Fd-3m), using the fullprof program. On assuming 3+ oxidation state for half of iron and whole of gallium, the chemical composition of the oxynitride spinel determined by the X-ray analysis is Fe2GaN2O2. The refinement using these parameters resulted in a good fit to the observed diffraction data, with a crystallographic R factor of 5.92. This ternary oxynitride of iron and gallium is a novel material which can give unique optical and magnetic properties.

Growth and characterization of (Bi, Pb)2Sr2Ca2Cu3Oxsingle crystals

1998 ◽  
Vol 13 (3) ◽  
pp. 589-595 ◽  
Author(s):  
Shaoyan Chu ◽  
Michael E. McHenry
Keyword(s):  
Detection Limit ◽  
Chemical Composition ◽  
Crystal Orientation ◽  
Impurity Phase ◽  
Squid Magnetometry ◽  
X Ray Diffraction ◽  
Phase Purity ◽  
Relative Fraction ◽  
X Ray

(Bi, Pb)2Sr2Ca2Cu3Ox (2223) single crystals have been grown using a fused-salt reaction of Bi2O3, PbO, SrCl2, CaCl2, CuCl, and KNO3 in a KCl flux. The pristine crystals show regular plate-like morphology with typical dimension of 0.1 × 0.1 × 0.001–0.01 mm3. Crystal orientation, chemical composition, phase purity, and superconductivity of the pristine crystals were determined by SEM, TEM, EDX, x-ray diffraction techniques, and SQUID magnetometry. The relative fraction of the Bi-2223 phase (Tc = 110 K) in as-grown crystals is ~97%. The only impurity phase, Bi-2212, occurs in some selected crystals but is present in amounts less than the detection limit of x-ray diffraction and is unobserved in the diamagnetic signal determined by SQUID magnetometry.

scholarly journals Field-induced single-ion magnet based on a quasi-octahedral Co(II) complex with mixed sulfur-oxygen coordination environment

2021 ◽  
Author(s):  
Denis V. Korchagin ◽  
Yaroslav E. Gureev ◽  
Elena A. Yureva ◽  
Gennady V. Shilov ◽  
Alexander V. Akimov ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Octahedral Complex ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Coordination Environment ◽  
X Ray ◽  
Oxygen Coordination

Synthesis and characterization of structure and magnetic properties of the quasi-octahedral complex (pipH2)[Co(TDA)2] 2H2O (I), (pipH22+ = piperazine dication, TDA2-= thiodiacetic anion) are described. X-ray diffraction studies reveal the first...

Investigations of Microstructure and Phase Composition of Different Self-Shield Flux-Cored Wire Slag System

2016 ◽  
Vol 850 ◽  
pp. 748-754 ◽  
Author(s):  
Jiang Long Yi ◽  
Xin Xin Wang ◽  
Kai Wang ◽  
Shi Da Zheng ◽  
He Xin Chen ◽  
...  
Keyword(s):  
Phase Composition ◽  
Chemical Composition ◽  
Grain Boundary ◽  
Phase Structure ◽  
Slag System ◽  
Framework Structure ◽  
X Ray Diffraction ◽  
Cored Wire ◽  
X Ray

A series of slag were fabricated by self-shield welding of different flux-cored wire. The microstructure and phase composition of those slag were investigated by means of metallographic microscope, SEM,EDX and X-ray diffraction respectively. The result demonstrated that the slag forming material of TiO2 and Al2O3 tenders to form the framework structure of slag, while CaO and MnO2 inclines to incorporate in the grain boundary. Furthermore, the dense and dendrite phase structure of slag was beneficial for the removal of slag. On the contrary the slag with tiny needle and skeleton-like structure was difficult to clear up. In conclusion, the detachability performance was not only affected by the microstructure, but also by the chemical composition of the slag system.

Magnetic Properties of Pb2Sr2Eu1-xCaxCu308+z Superconductors

1989 ◽  
Vol 169 ◽  
Author(s):  
C.D. Nelson ◽  
W.P. Pratt ◽  
P.P. Vaishnava
Keyword(s):  
Magnetic Properties ◽  
Transition Temperature ◽  
Single Phase ◽  
Magnetic Measurements ◽  
Meissner Effect ◽  
Impurity Phase ◽  
Squid Magnetometer ◽  
Shielding Effect ◽  
X Ray Diffraction ◽  
X Ray

AbstractX-ray diffraction and magnetic measurements using a SQUID magnetometer have been performed on the title compounds for 0 ≤ x ≤ 0.9. For 0 ≤ x ≤ 0.5, we have single phase materials. However, a small percentage of an impurity phase is noticed in the x = 0.7 sample, and the x = 0.9 sample is clearly not a single phase material. The transition temperature, the diamagnetic-shielding effect, and the Meissner-effect increase as x becomes larger. We have obtained, approximately, Hc1 ≤ 700 oe and Hc2 ≥ 800 k0e.

Study the Effect of the Substitution of Ba with Pr in Barium Ferrite Powder on Magnetic Properties

2014 ◽  
Vol 1025-1026 ◽  
pp. 440-444
Author(s):  
Pornpen Marawichayo ◽  
Wirunya Keawwattana ◽  
Nattamon Koonsaeng ◽  
Pongsakorn Jantaratana
Keyword(s):  
Magnetic Properties ◽  
Coercive Field ◽  
Barium Ferrite ◽  
Barium Hexaferrite ◽  
Ferrite Powder ◽  
X Ray Diffraction ◽  
One Pot ◽  
X Ray ◽  
Saturation Magnetisation ◽  
Substituted Barium Hexaferrite

Pr substituted barium hexaferrite, Ba1-xPrxFe12O19 with x = 0.00-0.20 were synthesized by Oxide One Pot Synthesis (OOPS) process. The phase composition of Ba1-xPrxFe12O19 were characterized by X-ray diffraction analysis (XRD). The phase morphology of the barium hexaferrite powder was studied by scanning electron microscope (SEM) and energy dispersive X-ray (EDX) spectroscopy confirmed that the Pr completely substituted into barium ferrite. The magnetic properties was investigated by vibrating sample magnetometry (VSM). It was found that saturation magnetisation and coercive field can be improved by the substitution of Ba with Pr in BaFe12O19 powder. The saturation magnetisation increased at first to the maximum of 50 emu g-1 (x = 0.15) and then decreased to the 34 emu g-1 (x = 0.20), while the coercive field increased remarkably with increasing Pr ions content.

scholarly journals Исследование особенностей состава, магнитной и кристаллической структуры гексаферрита бария BaFe-=SUB=-12-x-=/SUB=-Ti-=SUB=-x-=/SUB=-O-=SUB=-19-=/SUB=-

2020 ◽  
Vol 62 (5) ◽  
pp. 789
Author(s):  
В.В. Коровушкин ◽  
А.В. Труханов ◽  
В.Г. Костишин ◽  
И.М. Исаев ◽  
И.В. Щетинин ◽  
...  
Keyword(s):  
Mössbauer Spectroscopy ◽  
Mossbauer Spectroscopy ◽  
Barium Hexaferrite ◽  
Partial Substitution ◽  
Isomorphic Substitution ◽  
Charge Balance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mößbauer Spectroscopy ◽  
Substituted Barium Hexaferrite

The results of studies of the composition, crystal, and magnetic structure of Ti-substituted barium hexaferrite BaFe12 - xTixO19 (0.25<x<1.5) by Mössbauer spectroscopy, vibration magnetometry, X-ray diffraction, and synchronous thermal analysis are presented. Partial substitution of Fe3 + ions by Ti4 + ions revealed the presence of a limited heterovalent isomorphism realized according to the 2Fe3+ = Ti4+ + Fe2+ while maintaining charge balance. Using Mössbauer spectroscopy, an increase in the electron density of 3d electrons and the presence of Fe2+ in BaFe12 - xTixO19 samples with x = 1.5 were established. The limit of heterovalent isomorphic substitution is established, which is in the range 0.75 <x <1.0. Using Mössbauer spectroscopy and X-ray diffraction, the formation of titanium-containing phases at x = 1, 0, the content of which increases with increasing degree of substitution, is shown. Information is provided on the predominant distribution of substituent ions (Ti4+) in the structure of barium hexaferrite at positions 12k and 2b.

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