scholarly journals Novel Orange Color Pigments Based on La3LiMnO7

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6243
Author(s):  
Ryohei Oka ◽  
Jun-ichi Koyama ◽  
Takuro Morimoto ◽  
Toshiyuki Masui
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Toxic Elements ◽  
Single Phase ◽  
Solid State Reaction Method ◽  
Orange Pigment ◽  
Phase Form ◽  
B Values ◽  
Reaction Method ◽  
Orange Color

La3LiMn1−xTixO7 (0 ≤ x ≤ 0.05) samples were synthesized by a solid-state reaction method, and a single-phase form was observed for the samples in the range of x ≤ 0.03. Crystal structure, optical properties, and color of the La3LiMn1−xTixO7 (0 ≤ x ≤ 0.03) samples were characterized. Strong optical absorption was observed at a wavelength between 400 and 550 nm, and a shoulder absorption peak also appeared around 690 nm in all samples; orange colors were also exhibited. Among the samples synthesized, the most brilliant orange color was obtained at La3LiMn0.97Ti0.03O7. The redness (a*) and yellowness (b*) values of this pigment were higher than those of the commercially available orange pigments. Therefore, the orange color of this pigment is brighter than those of the commercial products. Since the La3LiMn0.97Ti0.03O pigment is composed of non-toxic elements, it could be a new environmentally friendly inorganic orange pigment.

scholarly journals Thermoelectric Study of La2Ti2-xNbxO7 (0≤x≤0.25) Ceramic Materials

2020 ◽  
pp. 38-47
Author(s):  
A. C. Iyasara ◽  
F. U. Idu ◽  
E. O. Nwabineli ◽  
T. C. Azubuike ◽  
C. V. Arinze
Keyword(s):  
Crystal Structure ◽  
Thermal Conductivity ◽  
Solid State ◽  
Single Phase ◽  
Ceramic Materials ◽  
Solid State Reaction Method ◽  
Reaction Method ◽  
Reducing Atmosphere ◽  
High Seebeck Coefficient ◽  
Porous Microstructures

La2Ti2-xNbxO7 (x = 0.00, 0.05, 0.10, 0.15, 0.20, 0.25) powders were synthesised via solid state reaction method, followed by sintering at 1673 K in a reducing atmosphere of 5% H2/N2 gas. The crystal structure, microstructure and thermoelectric (TE) properties of the pure and Nb-doped La2Ti2O7 ceramics were investigated. All compositions were single phase with porous microstructures consistent with their low experimental densities. Thermoelectric results of Nb-doped compositions showed improved properties in comparison to pure La2Ti2O7, suggesting that cation doping has the potential to improve the thermoelectric properties. Generally, the TE results obtained are not suitable for thermoelectric applications. However, the high Seebeck coefficient (≥190 μV/K) and glass-like thermal conductivity ( ≤2.26 w / m.k )  values achieved have opened a new window for exploring the thermoelectric potentials of La2Ti2O7 and other related oxides.

Effects of Various Fluxes on Synthesis of Deep Red Emitting CaAl12O19:Mn4+ Phosphors

2016 ◽  
Vol 852 ◽  
pp. 454-460 ◽  
Author(s):  
Qiu Hong Zhang ◽  
Hai Yong Ni ◽  
Ling Li Wang ◽  
Fang Ming Xiao
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Solid State Reaction ◽  
Single Phase ◽  
Luminescent Properties ◽  
Solid State Reaction Method ◽  
Luminescent Intensity ◽  
Reaction Method ◽  
Structure Morphology ◽  
Forming Temperature

Deep red emitting CaAl12-xO19:xMn4+ phosphors were synthesized by solid state reaction method. Various fluxes (BaF2, H3BO3, Na2CO3 and NH4Cl) were added in preparation of the phosphors. The influences of the various fluxes on the crystal structure, morphology and luminescent properties of CaAl12O19:Mn4+ phosphors were studied. The results show that the obtained phosphors with fluxes possessed better luminescent intensity than that of the phosphors without fluxes. The maximum luminescent intensities were found with the following order: H3BO3 (2.0 wt%) > Na2CO3 (0.5 wt%) > NH4Cl (0.3 wt%) > BaF2 (0.1 wt%) > no flux. The H3BO3 flux can decrease the single phase forming temperature of CaAl12O19:Mn4+ phosphors by about 150°C.

Synthesis and Characterization of Mg2Si Thermoelectric Material

2013 ◽  
Vol 802 ◽  
pp. 213-217 ◽  
Author(s):  
Chalida Nakhowong ◽  
Teerawut Sumpao ◽  
Tosawat Seetawan
Keyword(s):  
Crystal Structure ◽  
Single Phase ◽  
Solid State Reaction Method ◽  
Argon Atmosphere ◽  
Synthesis And Characterization ◽  
Mixed Powder ◽  
Reaction Method ◽  
Cubic Structure ◽  
Structure And Microstructure

The Mg2Si compound was synthesized by the solid state reaction method. The powder precursors of Mg and Si were thoroughly mixed in ballmilling for 24 hr in an argon atmosphere. Mixed powder was pressed at 170MPa and sintered at 800 °C for 6 hr in an argon atmosphere. The sinter powder was crushed in mortar for 1 hr. The crystal structure and microstructure were measured and observed by using XRD and SEM. The microstructure and the crystal structure were analyzed. TheMg2Si shows single phase, cubic structure and particle size about 1-10 mm.

scholarly journals Thermoelectric Study of La2Ti2-xNbxO7 (0 ≤ x ≤ 0.25) Ceramics

2020 ◽  
Author(s):  
Adindu Cyril Iyasara ◽  
Felix U Idu
Keyword(s):  
Crystal Structure ◽  
Thermal Conductivity ◽  
Solid State ◽  
Seebeck Coefficient ◽  
Single Phase ◽  
Solid State Reaction Method ◽  
Reaction Method ◽  
Reducing Atmosphere ◽  
High Seebeck Coefficient ◽  
Porous Microstructures

Abstract La2Ti2 − xNbxO7 (x = 0.00, 0.05, 0.10, 0.15, 0.20, 0.25) powders were synthesised via solid state reaction method, followed by sintering at 1673 K in a reducing atmosphere of 5% H2/N2 gas. The crystal structure, microstructure and thermoelectric (TE) properties of the pure and Nb-doped La2Ti2O7 ceramics were investigated. All compositions were single phase with porous microstructures consistent with their low experimental densities. Thermoelectric results of Nb-doped compositions showed improved properties in comparison to pure La2Ti2O7, suggesting that cation doping has the potential to improve the thermoelectric properties. Generally, the TE results obtained are not suitable for thermoelectric applications. However, the high Seebeck coefficient ( \ge 190 µV/K) and glass-like thermal conductivity ( \le 2.26 \text{W}/\text{m}.\text{K}) values achieved have opened a new window for exploring the thermoelectric potentials of La2Ti2O7 and other related oxides.

The Effect of x Mole Ratio on Crystal Structure and Characteristic of Microwave Absorption of ZnLaxFe(2-x)O4 System

2020 ◽  
Vol 855 ◽  
pp. 46-51
Author(s):  
Yunasfi ◽  
Ari Adi Wisnu ◽  
Mashadi ◽  
Deswita ◽  
Yana Taryana
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Microwave Absorption ◽  
Spinel Structure ◽  
Single Phase ◽  
Solid State Reaction Method ◽  
Local Production ◽  
Reaction Method ◽  
Sem Image ◽  
Absorbing Material

The effect of x mole ratio on crystal structure and characteristic of microwave absorption of ZnLaxFe(2-x)O4 system (x = 0.0; 0.01and 0.02) synthesized by solid state reaction method has been studied. The series of ZnLaxFe(2-x)O4 samples were prepared using ZnO (99.99%) and Fe2O3 (99.99 %) powders (Merck product), while La2O3 (local production) powders in mole ratio. The identification result of the XRD shows that all of samples are single phase in this stage, it has cubic spinel structure with space group F d-3 m. The SEM image of ZnLaxFe(2-x)O4 samples appear that the increase of mole ratio, the particle size of the compound powder rapidly becomes bigger, homogeneous and not uniform powder with spherical in shape and particle size of 200-500 nm. The results of the VNA characterization shows that the increasing of mole ratio (x = 0.0; 0.01 and 0.02) will enhance the ability to absorb microwave from 90.35% upto 97.69%. Thus. the composition of x=0.02 (ZnLa0.02Fe1.98O4) possess to be the best composition for microwave absorbing material.

scholarly journals Structure and electric properties of cerium substituted SrBi1.8Ce0.2Nb2O9 and SrBi1.8Ce0.2Ta2O9 ceramics

2016 ◽  
Vol 10 (3) ◽  
pp. 183-188 ◽  
Author(s):  
Mohamed Afqir ◽  
Amina Tachafine ◽  
Didier Fasquelle ◽  
Mohamed Elaatmani ◽  
Jean-Claude Carru ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Solid State ◽  
Room Temperature ◽  
Single Phase ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Lcr Meter ◽  
Curie Temperature Tc

SrBi1.8Ce0.2Nb2O9 (SBCN) and SrBi1.8Ce0.2Ta2O9 (SBCT) powders were prepared via solid-state reaction method. X-ray diffraction analysis reveals that the SBCN and SBCT powders have the single phase orthorhom-bic Aurivillius structure at room temperature. The contribution of Raman scattering and FTIR spectroscopy of these samples were relatively smooth and resemble each other. The calcined powders were uniaxially pressed and sintered at 1250?C for 8 h to obtaine dense ceramics. Dielectric constant, loss tangent and AC conductivity of the sintered Ce-doped SrBi2Nb2O9 and SrBi2Ta2O9 ceramics were measured by LCR meter. The Ce-doped SBN (SBCN) ceramics have a higher Curie temperature (TC) and dielectric constant at TC (380?C and ?? ~3510) compared to the Ce-doped SBT (SBCT) ceramics (330?C and ?? ~115) when measured at 100Hz. However, the Ce-doped SBT (SBCT) ceramics have lower conductivity and dielectric loss.

Synthetic Processes via Complex Precursors of Rare Earth Manganites with the Perovskite and its Related Structures

2004 ◽  
Vol 449-452 ◽  
pp. 725-728 ◽  
Author(s):  
A. Shimono ◽  
Hirohisa Sato ◽  
K. Kawada-Wada ◽  
Yasuo Ito ◽  
Naoki Kamegashira
Keyword(s):  
Rare Earth ◽  
Single Phase ◽  
Solid State Reaction Method ◽  
Rare Earth Complex ◽  
Normal Process ◽  
Composition Region ◽  
Synthetic Process ◽  
Reaction Method ◽  
X Ray ◽  
Rare Earth Manganites

A development of synthetic process via rare earth complex precursors was applied to a formation of rare earth manganites which can not be easily formed by conventional (normal) process. Several compounds of rare earth manganites with various structures were successfully synthesized by this method and their crystal structures were identified by powder X-ray diffractometry. Both of the orthorhombic and rhombohedral LaMnO3phases were prepared. LnMn2O5phase was more easily prepared by this method than by another method. The solid solution of (Sr,La)2MnO4phase for various compositions were tried to prepare a single phase, especially for a composition region Sr/La ratio < 1. since this phase is normally formed for only region of Sr/La ratio .. 1 by the solid state reaction method.

Thermal enhancement of 2H11/2→4I15/2 up-conversion luminescence of Er3+ doped K2Yb(PO4)(MoO4) phosphors

2021 ◽  
Author(s):  
Hongqiang Cui ◽  
Yongze Cao ◽  
Lei Zhang ◽  
Yuhang Zhang ◽  
Siying Ran ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Solid State Reaction ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Orthorhombic Crystal ◽  
Orthorhombic Crystal Structure ◽  
Reaction Method ◽  
X Ray ◽  
Thermal Enhancement

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...

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