Features of crystal structure and phase composition of the anisotropic hexagonal ferrites bafe12o19 and bafe9,5al2,5o19, obtained by radiation-thermal sintering

2016 ◽  
Author(s):  
Пашков ◽  
A. Pashkov ◽  
Костишин ◽  
V. Kostishin ◽  
Исаев ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Beam ◽  
Phase Composition ◽  
Sintering Temperature ◽  
Barium Hexaferrite ◽  
Hexagonal Ferrites ◽  
X Ray ◽  
Fast Electron Beam ◽  
Thermal Sintering ◽  
Substituted Barium Hexaferrite

The method of radiation-thermal sintering (RTS) in the fast electron beam by accelerator ILU-6 obtained samples of barium hexaferrite BaFe12O19 and substituted barium hexaferrite BaFe9,5Al2,5O19 (with additions of Ni, Ti, Mn). The research synthesized samples was carried out by X-ray structural analysis and X-ray phase analysis. It is found that both compounds besides the main phase samples (BaFe12O19 and BaFe9,5Al2,5O19, respectively), is also present phase BaFe2O4. With increasing sintering temperature from 1100°C to 1300°C phase barium monoferrite intensity decreases or disappears completely, and at a temperature of 1400°C this phase is fixed again (its intensity continues to increase). The possibility of practical use of the results.

scholarly journals Электрофизические и диэлектрические свойства поликристаллов железо-иттриевого феррита-граната, полученных по технологии радиационно-термического спекания

2021 ◽  
Vol 63 (3) ◽  
pp. 356
Author(s):  
В.Г. Костишин ◽  
Р.И. Шакирзянов ◽  
А.Г. Налогин ◽  
С.В. Щербаков ◽  
И.М. Исаев ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Loss Tangent ◽  
Sintering Temperature ◽  
Ceramic Technology ◽  
Complex Dielectric Constant ◽  
Temperature Dependences ◽  
Fast Electron Beam ◽  
Electrical And Dielectric Properties ◽  
Thermal Sintering ◽  
Iron Garnet

In this paper the electrical and dielectric properties of polycrystalline yttrium iron garnet, obtained by the radiation-thermal sintering technology in a fast electron beam were investigated. Spectra of complex dielectric constant, dielectric loss tangent and conductivity were measured in the frequency range 25 – 1∙106 Hz. For comparison, DC resistance measurements were also performed. The temperature dependences of the above parameters were measured at frequencies of 1 kHz, 100 kHz in the range 25 - 300 °C. It is shown, that conduction activations energy, permittivity, loss tangent and resistance vary significantly from sintering temperature in the range of 1300 to 1450 °C. It is found that with an increase in the sintering temperature to 1450 °C, dielectric properties are the same as samples made by the traditional ceramic technology.

scholarly journals Люминофоры холодного голубого излучения на основе оксида алюминия, допированного диспрозием

2022 ◽  
Vol 64 (1) ◽  
pp. 95
Author(s):  
И.В. Бакланова ◽  
В.Н. Красильников ◽  
А.П. Тютюнник ◽  
Я.В. Бакланова
Keyword(s):  
Crystal Structure ◽  
Phase Composition ◽  
Diffraction Analysis ◽  
Powder Diffraction ◽  
Thermal Quenching ◽  
Emission Spectra ◽  
X Ray ◽  
White Emission ◽  
Uv Excitation ◽  
Quenching Of Luminescence

Al2О3:Dy3+ oxides with different colors luminescence were synthesized using precursor technology. The phase composition and crystal structure of the obtained materials were established by X-ray powder diffraction analysis. The excitation and emission spectra, decay curves, thermal quenching of luminescence were studied. Under UV excitation, the phosphors exhibit blue, purplish blue, white emission depending on the concentration of dysprosium and the temperature of annealing of the Al1-xDyx(OH)(HCOO)2 precursor in air.

Study on the Properties of Doped La in BaBi4Ti4O15 Ceramic

2007 ◽  
Vol 26-28 ◽  
pp. 243-246
Author(s):  
Xing Hua Yang ◽  
Jin Liang Huang ◽  
Xiao Wang ◽  
Chun Wei Cui
Keyword(s):  
Crystal Structure ◽  
Grain Size ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Sintering Temperature ◽  
Solid Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lanthanum Content ◽  
Scanning Electron

BaBi4-xLaxTi4O15 (BBLT) ceramics were prepared by conventional solid phase sintering ceramics processing technology. The crystal structure and the microstructure were detected by X-ray diffraction (XRD) and scanning electron microscope (SEM). The XRD analyses show that La3+ ions doping did not change the crystal structure of BBT ceramics. The sintering temperature increased from 1120°C to 1150°C with increasing Lanthanum content from 0 to 0.5, but it widened the sintering temperature range from 20°C to 50°C and refined the grain size of the BBT ceramic. Additionally, polarization treatment was performed and finally piezoelectric property was measured. As a result, the piezoelectric constant d33 of the 0.1at.% doped BBLT ceramics reached its highest value about 22pc/N at polarizing electric field of 8kV/mm and polarizing temperature of 120°C for 30min.

Effects of Electron Beam on Structure and Physical Properties of Natural Colorless Topaz

2015 ◽  
Vol 1125 ◽  
pp. 60-63
Author(s):  
Chutharat Paikaew ◽  
Juthamas Inthanont ◽  
Adisak Punyanut ◽  
Ekachai Hoonnivathana ◽  
Pichet Limsuwan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Beam ◽  
Physical Properties ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spin Resonance ◽  
Function Group ◽  
And Function ◽  
Beam Dose

The purpose of this research was to investigate physical properties, configuration and color of topaz. Topazes were irradiated with electron beam linear accelerator at different dose from 40 to 180 MGy. The color of topaz was analyzed by UV-vis and it was shown that the color of topaz was becoming strong color with increased electron beam dose. Crystal structure and function group of topaz were characterized by X- ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The results showed that the topaz has orthorhombic structure and no other crystalline. After irradiated, topaz released OH indicating higher crystallinity of topaz and this was confirmed with the results of electron spin resonance (ESR). Electron beam dose response of topaz was investigated. ESR results showed that the Al3+ ion was substituted in Si4+ site and Ti3+ impurity in Al4+ site and this result corresponds to the results of FTIR. The experiment result indicated that electron beam could be making defect on crystal structure and color enhancement of topaz.

Effect of Sintering Temperatures and Ba/Ti Ratio on Dielectric Properties of BaTiO3 Ceramic

2013 ◽  
Vol 750-752 ◽  
pp. 506-511
Author(s):  
Yuan Yuan Li ◽  
Gui Xia Dong ◽  
Bi Yan Zhu ◽  
Qiu Xiang Liu ◽  
Di Wu
Keyword(s):  
Crystal Structure ◽  
Dielectric Properties ◽  
Curie Temperature ◽  
Sintering Temperature ◽  
Solid Phase ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Method Effect

As a research object, the samples with various Ba/Ti ratios (Ba/Ti=0.95~1.05) were synthesized by solid phase reaction method. Effect of sintering temperatures and Ba/Ti ratio on dielectric properties and crystal structure of BaTiO3ceramic were investigated. Crystal structure and crystal phase composition were investigated by scanning electron microscopy and X-ray diffraction. The dielectric properties were studied by Agilent 4294A at 1 kHz. The results show that the BaTiO3ceramic has high permittivity and dielectric loss at 1340°C. The permittivity of BaTiO3ceramic with Ba/Ti=0.95 change small as the sintering temperatures vary at 1320°C. With the increasing of Ba/Ti ratio, the Curie temperature first increases and then decreases as the sample sintering at 1320°C. When Ba/Ti=1, the Curie temperature increase with the sintering temperature increasing.

Spark Plasma Sintering of Paper-Derived Ti3AlC2-Based Composites: Influence of Sintering Temperature

2021 ◽  
Vol 1016 ◽  
pp. 1790-1796
Author(s):  
Maxim Syrtanov ◽  
Egor Kashkarov ◽  
Tatyana Murashkina ◽  
Nahum Travitzky
Keyword(s):  
Phase Composition ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Total Content ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbide Phases ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Scanning Electron

This paper describes the influence of sintering temperature on phase composition and microstructure of paper-derived Ti3AlC2 composites fabricated by spark plasma sintering. The composites were sintered at 100 MPa pressure in the temperature range of 1150-1350 °C. Phase composition and microstructure were analyzed by X-ray diffraction and scanning electron microscopy, respectively. The multiphase structure was observed in the sintered composites consisting of Ti3AlC2, Ti2AlC, TiC and Al2O3 phases. The decomposition of the Ti3AlC2 phase into Ti2AlC and TiC carbide phases was observed with temperature rise. The total content of Ti3AlC2 and Ti2AlC phases was reduced from 84.5 vol.% (1150 °C) to 69.5 vol.% (1350 °C). The density of composites affected by both the content of TiC phase and changes in porosity.

Structure of Carbonated Hydroxyapatite Based on Rietveld Method

2008 ◽  
Vol 368-372 ◽  
pp. 1187-1189
Author(s):  
Xu Ran ◽  
Jun Guo Ran ◽  
Li Gou ◽  
Ji Yong Chen ◽  
Jiao Min Luo
Keyword(s):  
Crystal Structure ◽  
Sintering Temperature ◽  
Rietveld Method ◽  
Rietveld Analysis ◽  
Structure Parameters ◽  
X Ray Diffraction ◽  
Carbonated Hydroxyapatite ◽  
X Ray ◽  
Quantitative Results ◽  
Distortion Index

The crystalline structures of B-type carbonated hydroxyapatite (CHA) powders sintered at 700, 900 and 1100°C, respectively, were studied by Rietveld analysis of powder X-ray diffraction (XRD) data. A series of structure parameters, including lattice parameters (a and c), bond length and the distortion index of PO4 tetrahedron (Dind) were calculated by Rietveld method to characterize the fine structure of CHA. The broadening effect of XRD reflections was separated to calculate the micro-strain and crystalline size. The results showed that CHA become more stable with the increase of sintering temperature, but the CO3 2- is almost lost at temperature of 1100°C. The quantitative results about crystal structure of CHA based on crystalline structure simulated by Rietveld method are obtained.

Accuracy of XRPD QPA using the combined Rietveld–RIR method

2000 ◽  
Vol 33 (2) ◽  
pp. 267-278 ◽  
Author(s):  
Alessandro F. Gualtieri
Keyword(s):  
Crystal Structure ◽  
Phase Composition ◽  
Incoherent Scattering ◽  
Quantitative Phase Analysis ◽  
Polycrystalline Materials ◽  
Structure Model ◽  
Thermal Displacement ◽  
Model Assumption ◽  
Pyroclastic Rocks ◽  
X Ray

QPA (quantitative phase analysis) of polycrystalline materials using XRPD (X-ray powder diffraction) can be performed using the combined Rietveld and reference intensity ratio (RIR) methods, providing an estimate of both the crystalline and the amorphous phase in a mixture. Although the accuracy of estimates of the phase composition of simple ternary or quaternary mixtures is generally very good, uncertainties remain and bias the accuracy of phase determinations in complex systems such as pyroclastic rocks, which may contain two or more zeolite species, a number of other phases (generally up to four or five), and glass. The contribution of the incoherent scattering, biasing accuracy, in the glass determination has been discussed in an earlier work on the modal analysis of pyroclastic rocks [Gualtieri (1996).Powder Diffr.11, 97–106]. In this work, the assumption of the crystal structure, the influence of the spike addition, background and atomic (thermal) displacement parameters are discussed. It is shown that the structure-model assumption no longer holds for systems containing complex phases such as zeolites, as the accuracy is degraded and, as far as the influence of the added spike is concerned, there is an underestimation of the glass content with increasing amounts of added spike.

X-Ray Characterization and Crystal Structure of SBT Doped with V2O5

2011 ◽  
Vol 287-290 ◽  
pp. 608-612
Author(s):  
Su Hua Lv ◽  
Shu Lang Guo ◽  
Hua Ji
Keyword(s):  
Crystal Structure ◽  
Temperature Change ◽  
Sintering Temperature ◽  
Ferroelectric Materials ◽  
Reaction Sintering ◽  
Sintering Process ◽  
Solid Reaction ◽  
X Ray ◽  
Plate Shape

SBT Ferroelectric Materials are prepared by solid reaction sintering process after doping V2O5to SBT bulk and its properties are researched. The results show that this method can decrease sintering temperature , change the grains from rod to plate shape, increase grains size and lead to the grains growth with c-axis. And there are ferroelectric 90b domains in SBTV crystal .

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