Correlation between structure, surface defect chemistry and O18/O16 exchange for La2Mo2O9 and La2(MoO4)3

Author(s):  
Natalia M. Porotnikova ◽  
Maxim I. Vlasov ◽  
Yuri Zhukov ◽  
Christian Kirschfeld ◽  
Anna Khodimchuk ◽  
...  

The La2Mo2O9 and La2(MoO4)3 powders were synthesized by the solid-state reaction method and were used to prepare dense ceramics. X-ray photoelectron spectroscopy was used to study the chemical composition and...

Author(s):  
Hongqiang Cui ◽  
Yongze Cao ◽  
Lei Zhang ◽  
Yuhang Zhang ◽  
Siying Ran ◽  
...  

Er3+ with different concentrations doped K2Yb(PO4)(MoO4) phosphors were prepared by a solid-state reaction method, and the layered orthorhombic crystal structure of the samples was confirmed by X-ray diffraction (XRD). Under...


2021 ◽  
Vol 321 ◽  
pp. 23-27
Author(s):  
Simona Ravaszová ◽  
Karel Dvořák

The paper is focused on one of the most important component of Portland clinker-on the tricalcium silicate. The study reported in this article is focuses on the changes in crystallite size of synthetic tricalcium silicate obtained using solid state reaction method. Crystallite size changes are monitored during the grinding in three types of laboratory mills in two different conditions. Changing in crystallite size at various grinding time up to 120 minutes are studied with the aid of X-ray diffraction and using the Scherrer equation. It has been found that the most efficient laboratory mill in terms of speed and fineness of the material was the planetary mill.


2020 ◽  
Vol 18 (11) ◽  
pp. 14-18
Author(s):  
Abbas K. Saadon ◽  
Kareem A. Jasim ◽  
Auday H. Shaban

The high temperature superconductor’s compounds are one of the hot spot field of science, due to their applications in industries. Hg0.8Sb0.2Ba2Ca2Cu3O8+δ and Hg0.8Sb0.2Ba2Ca1Cu2O6+δ, were manufactured using a doable-step of solid state reaction method. The samples were sintered at 800 ° C. The transition temperatures Tc are found from electrically resistively by using four probe techniques. The resistivity become zero when the transition temperature Tc(offset) have 131 and 119 K, and the onset temperature Tc(onset) have 139 K for Hg0.8Sb0.2Ba2Ca2Cu3O8+δ and 132 K for Hg0.8Sb0.2Ba2Ca1Cu2O6+δ. Analysis of X-ray diffraction showed a tetragonal structure with lattice parameters changes for all samples.


2016 ◽  
Vol 16 (4) ◽  
pp. 3684-3689 ◽  
Author(s):  
Xin Min ◽  
Zhaohui Huang ◽  
Minghao Fang ◽  
Yan’gai Liu ◽  
Chao Tang ◽  
...  

In this paper, M3(VO4)2 (M = Mg, Ca, Sr, and Ba) self-activated phosphors were prepared by a solid-state reaction method at 1,000 °C for 5 h. The phase formation and micrographs were analyzed by X-ray diffraction and scanning electron microscopy. The Ca3(VO4)2 phosphor does not show any emission peaks under excitation with ultraviolet (UV) light. However, the M3(VO4)2 (M = Mg, Sr, and Ba) samples are effectively excited by UV light chips ranging from 200 nm to 400 nm and exhibit broad emission bands due to the charge transfer from the oxygen 2p orbital to the vacant 3d orbital of the vanadium in the VO4. The color of these phosphors changes from yellow to light blue via blue-green with increasing ionic radius from Mg to Sr to Ba. The luminescence lifetimes and quantum yield decrease with the increasing unit cell volume and V–V distance, in the order of Mg3(VO4)2 to Sr3(VO4)2 to Ba3(VO4)2. The emission intensity decreases with the increase of temperatures, but presents no color shift. This confirms that these self-activated M3(VO4)2 phosphors can be suggested as candidates of the single-phase phosphors for light using UV light emitting diodes (LEDs).


2020 ◽  
Vol 42 (3) ◽  
pp. 363-363
Author(s):  
Mohammed A B Abdul jabar and Ignatov A V Mohammed A B Abdul jabar and Ignatov A V

The synthesis of solid solutions lead hydroxyapatite, Pb10(PO4)6*y(OH)2, were successfully synthesized by solid-state reaction (ceramic method) (y= 0.95; 0.96; 0.97; 0.98; 0.99 and 1.00) and precipitation (semi ceramic method) (y= 0.97; 0.98; 0.99 and 1.00) methods at 800 and#186;C for 50 hours. The X-ray powder diffraction (DRON-3m diffractometer), electron microscopy scanning (SEM) and energy dispersive X-ray micro-analysis which characterized all samples. It has been established that Pb10(PO4)5.82(OH)2 and Pb10(PO4)5.88(OH)2 are the best synthesis for lead hydroxyapatite in the solid-state reaction method, and Pb10(PO4)5.88(OH)2 is the precipitation method.


ALCHEMY ◽  
2018 ◽  
Vol 5 (1) ◽  
pp. 26
Author(s):  
Nur Aini ◽  
Rachamawati Ningsih

Anatase of Titanium dioxide (TiO<sub>2</sub>)  was doped with vanadium ions (V<sup>3+</sup>), at doping levels ranging from 0.3, 0.5 to 0.7 atomic percentage in order to increase its photocatalytic activity under visible light irradiation. Vanadium doped TiO<sub>2</sub> was synthesized by solid state reaction method. Its physicochemical properties characterized by powder X-ray diffraction (XRD) and UV-Vis diffuse reflectance spectroscopy (DRS). Doping with V(III) resulted in a single phase structure of anatase TiO<sub>2</sub> with nanosize crystal ranging from 53.06 to 59.59 nm. Vanadium doping also resulted in a red-shift of the photophysical response of TiO<sub>2</sub> that was reflected in an extended absorption in the visible light between 400 and 700 nm.


2020 ◽  
Vol 12 (3) ◽  
pp. 259-267
Author(s):  
K. Nahar ◽  
M. A. Hossain ◽  
P. Roy ◽  
M. N. I. Khan ◽  
S. S. Sikder

Crystalline La doped Cu-Zn ferrite with compositions Cu0.15Zn0.85LaxFe2-xO4 [ x = 0.00, 0.02, 0.04, 0.06 and 0.08] were synthesized by using conventional solid state reaction method technique. X-ray diffraction pattern (XRD), Crystalline La doped Cu-Zn ferrite with compositions Cu0.15Zn0.85LaxFe2-xO4 [x = 0.00, 0.02, 0.04, 0.06 and 0.08] were synthesized by using conventional solid state reaction method technique. X-ray diffraction pattern (XRD), scanning electron micrographs (SEM), hysteresis loop (M-H) curves and frequency dependent resistivity were employed to inspect the effect of La3+ doping on the structure, microstructure, magnetic and transport properties of the specimens. All the specimens exhibited fcc type cubic spinel structure where the particle size were within 500-1600 nm range. Magnetically ferromagnetic phenomenon was found for all the samples where the effect of La3+ doping consequence on the variation of various parameters like saturation magnetization (Ms), coercivity (Hc) and remanent magnetization (Mr). The resistivity tuned by frequency for all the samples presented the decreasing phenomenon with the increase of applied frequency.


2018 ◽  
Vol 56 (1A) ◽  
pp. 86
Author(s):  
Nguyen Van Khien

In this paper, we report the effect of Ca substitution on the structure and ferroelectric properties of BaZr0.2Ti0.8O3-Ba1-xCaxTiO3 (BZT-BCT). The BZT-BCT samples were synthesized by solid state reaction method. The X-ray results indicate that a phase structure competition appears in the Ca-substituted samples. Based on the hysteresis loops measured by Sawyer – Towermethod, we calculated the Ec and Pr values with the extreme value reaching 29.6 %. The ferroelectric properties of BZT-BCT materialstrongly depend on Ca concentration. The results may be related to a pinning effect concerning with the phase-structured competition in the material.


2009 ◽  
Vol 42 (2) ◽  
pp. 153-160 ◽  
Author(s):  
Zhèn Yáng ◽  
Ashley S. Harvey ◽  
Anna Infortuna ◽  
Ludwig J. Gauckler

Selected compositions of the Ba–Sr–Co–Fe–O system were synthesized from powders by the solid-state reaction method. Samples were equilibrated at 1273 K for 36 000 s in air. The resulting powders were characterized by X-ray diffraction (XRD) at room temperature and by high-temperaturein situXRD. The phases present in the BaxSr1−xCoyFe1−yO3−δsystem are outlined for 1273 K in air. For most of the quaternary compositions, the cubic perovskite is formed, except for the compositions withx= 1 (excludingy= 0.4),y= 1 andx,y= 0.8, where the phases mainly show hexagonal distortions, andx, y= 0, for which a predominant cubic phase is mixed with other phases.


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