scholarly journals Deep-red emitting Mg2TiO4:Mn4+ phosphor ceramics for plant lighting

2020 ◽  
Author(s):  
Zixin Wang ◽  
Hui Lin ◽  
Dawei Zhang ◽  
Yiming Shen ◽  
Yang Li ◽  
...  
Keyword(s):  
Room Temperature ◽  
Solid State Reaction Method ◽  
Peak Wavelength ◽  
Reaction Method ◽  
Blue Led ◽  
Crystal Field Strength ◽  
Light Region ◽  
Racah Parameters ◽  
Order Of Magnitude ◽  
Narrow Emission

Abstract In this study, deep-red emitting Mg2TiO4:Mn4+ phosphor ceramics were synthesized by the high temperature solid-state reaction method. The ceramics can be excited by the 465 nm blue light and had a narrow emission with a full width at half maximum (FWMH) value of 31 nm. The peak wavelength was located at 658 nm, which matched the demanded wavelength for photosynthesis. The crystal field strength (Dq) and the Racah parameters (B and C) were estimated by the Tanabe-Sugano diagram. The thermal conductivity of the Mg2Ti(0.999)O4:0.001Mn4+ ceramic was 7.535 W/(m·K) at room temperature, which was one order of magnitude higher than that of the traditional packaging method using the silicone gel. A set of phosphor converted LEDs were fabricated by mounting the phosphor ceramics onto the 460 nm blue LED chips and the CIE coordinates can move from the blue region to the purple light region with the thickness of the ceramic increasing. These results indicated that the Mg2TiO4:Mn4+ phosphor ceramic was suitable for plant lighting when combined with a blue LED chip.

scholarly journals Deep-red emitting Mg2TiO4:Mn4+ phosphor ceramics for plant lighting

2020 ◽  
Author(s):  
Zixin Wang ◽  
Hui LIN ◽  
Dawei Zhang ◽  
Yiming Shen ◽  
Yang Li ◽  
...  
Keyword(s):  
Room Temperature ◽  
Solid State Reaction Method ◽  
Peak Wavelength ◽  
Reaction Method ◽  
Blue Led ◽  
Crystal Field Strength ◽  
Light Region ◽  
Racah Parameters ◽  
Order Of Magnitude ◽  
Narrow Emission

Abstract In this study, deep red emitting Mg2TiO4:Mn4+ phosphor ceramics were synthesized by the high temperature solid-state reaction method. The ceramics can be excited by the 465 nm blue light and had a narrow emission with a full width at half maximum (FWMH) value of 31 nm. The peak wavelength was located at 658 nm, which matched the demanded wavelength for photosynthesis. The crystal field strength (Dq) and the Racah parameters (B and C) were estimated by Tanabe-Sugano diagram. The thermal conductivity of the Mg2Ti(0.999)O4: 0.001Mn4+ ceramic was 7.535 W/(m·K) at room temperature, which was one order of magnitude higher than that of the traditional packaging method using the silicone gel. A set of phosphor converted LEDs were fabricated by mounting the phosphor ceramics onto the 460 nm blue LED chips and the CIE coordinates can move from the blue region to the purple light region with the thickness of the ceramic increasing. These results indicated that the Mg2TiO4:Mn4+ phosphor ceramic was suitable for plant lighting when combined with a blue LED chip.

scholarly journals Deep-red emitting Mg2TiO4:Mn4+ phosphor ceramics for plant lighting

2020 ◽  
Author(s):  
Zixin Wang ◽  
Hui LIN ◽  
Dawei Zhang ◽  
Yiming Shen ◽  
Yang Li ◽  
...  
Keyword(s):  
Blue Light ◽  
Room Temperature ◽  
Solid State Reaction Method ◽  
Peak Wavelength ◽  
Blue Led ◽  
Crystal Field Strength ◽  
Light Region ◽  
Racah Parameters ◽  
Order Of Magnitude ◽  
Narrow Emission

Abstract In this study, deep red emitting Mg2TiO4:Mn4+ phosphor ceramics were synthesized by the high temperature solid-state reaction method. The ceramics can be excited by the 465 nm blue light and had a narrow emission with a full width at half maximum (FWMH) value of 31 nm. The peak wavelength was located at 658 nm, which matched the most efficient wavelength for photosynthesis. The crystal field strength (Dq) and the Racah parameters (B and C) are estimated by Tanabe-Sugano diagram. The thermal conductivity of the ceramics was 7.535 W/(m·K) at room temperature, which was one order of magnitude higher than that of the traditional packaging method using silicone gel. A set of phosphor converted LEDs were fabricated by mounting the phosphor ceramics onto the 460 nm blue LED chips and the CIE coordinates can move from the blue light region to the purple light region with the thickness of the ceramic increasing. These results indicated that the Mg2TiO4:Mn4+ phosphor ceramic was suitable for plant lighting when combined with a blue LED chip.

Facile preparation of polyoxometalate nanoparticles via a solid-state chemical reaction for aerobic oxidative desulfurization catalysis

2021 ◽  
Author(s):  
Hang Yu ◽  
Wenwen Bu ◽  
Zijia Wang ◽  
Zhuoyue Zhao ◽  
Mehwish Jadoon ◽  
...  
Keyword(s):  
Solid State ◽  
Silver Nitrate ◽  
Chemical Reaction ◽  
Solid State Reaction ◽  
Room Temperature ◽  
Oxidative Desulfurization ◽  
Solid State Reaction Method ◽  
Reaction Method ◽  
State Chemical ◽  
Facile Preparation

Polyoxometalate nanoparticles were synthesized via a concise solid-state reaction method by directly grinding silver nitrate and the polyoxometalate (NH4)5H6PMo4V8O40 at room temperature without the assistance of a surfactant.

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.

Effect of Gd Substitution on the Dielectric Properties and Magnetoelectric Effect of BiFeO3

2010 ◽  
Vol 150-151 ◽  
pp. 1470-1475
Author(s):  
Gui Lin Song ◽  
Tian Xing Wang ◽  
Cun Jun Xia ◽  
Chao Li ◽  
Fang Gao Chang
Keyword(s):  
Dielectric Constant ◽  
Rare Earth ◽  
Dielectric Loss ◽  
Room Temperature ◽  
Magnetoelectric Effect ◽  
Solid State Reaction Method ◽  
Impurity Phase ◽  
Conventional Solid State Reaction ◽  
Reaction Method ◽  
Dielectric Relaxation Process

Multiferroic Bi1-xGdxFeO3(x=0, 0.05, 0.1, 0.15, 0.2) ceramics were prepared by conventional solid state reaction method. For all the samples prepared, they exhibit magnetoelectric effect at room temperature, and the dielectric constant and dielectric loss decrease with increasing frequency in the range from 10000Hz to 1 MHz from a typical orientational dielectric relaxation process. It has been found that both dielectric constant and dielectric loss are strongly dependent on the Gd3+ content. And substitution of Bi with rare earth Gd helps to eliminate the impurity phase in BiFeO3 ceramics.,

Investigation of Optical Properties of ZnO/MnO2, ZnO/TiO2 and ZnO/MnO2/TiO2 Nanocomposites

2014 ◽  
Vol 938 ◽  
pp. 123-127 ◽  
Author(s):  
G. Shanmuganathan ◽  
I.B. Shameem Banu
Keyword(s):  
Optical Properties ◽  
Room Temperature ◽  
Optical Band Gap ◽  
Energy Gap ◽  
Visible Region ◽  
Solid State Reaction Method ◽  
Morphological Properties ◽  
Energy Dispersive Analysis ◽  
Reaction Method ◽  
Uv Visible

ZnO nanocomposites such as (ZnO)0.8(MnO2)0.2, (ZnO)0.8(TiO2)0.2and (ZnO)0.8(MnO2)0.1(TiO2)0.1were prepared by solid state reaction method at room temperature. The structural analysis was carried out with help of powder XRD to confirm the formation of the composites. The morphological properties and presence of elemental compositions were analyzed with scanning electron microscope and energy dispersive analysis spectroscopy respectively. Optical properties were studied with UV visible spectrophotometer. From the transmittance spectrum, it is concluded that the synthesized composite materials have the transmittance in the range of 80 to 95% in the visible region. The calculated optical band gap values for pure ZnO is 3.16 eV and the values are 3.7eV, 5.27eV and 4.46eV for the composites ZnO/MnO2, ZnO/TiO2and ZnO/MnO2/TiO2, respectively. The study has found that the ZnO/MnO2, ZnO/TiO2and ZnO/MnO2/TiO2composites have very large energy gap as that of insulator.

scholarly journals RAMAN SPECTROSCOPY OF CaCu3Ti4O12 CERAMICS REVISITED

2018 ◽  
Vol 34 (3) ◽  
Author(s):  
Nhat Hoang Nam
Keyword(s):  
Raman Spectroscopy ◽  
Room Temperature ◽  
Structural Characteristics ◽  
Double Perovskite ◽  
Solid State Reaction Method ◽  
Excess Oxygen ◽  
Optical Phonons ◽  
Reaction Method ◽  
Colossal Dielectric Constant ◽  
Perovskite Type

The CaCu3Ti4O12 ceramic has been prepared by Solid State Reaction method in excess oxygen. It possesses a well-defined double-perovskite type crystalline structure and exhibits a colossal dielectric constant at around 50000 at room temperature. This paper revised the imprints of Raman spectroscopy of this compound to validate its structural characteristics and optical behaviors. A special attention is paid on the account of optical phonons which show a recognizable agreement with the other results recently reported

scholarly journals Thermoelectric properties of LaFeO3 system with doped Ti, Co, Cu

2017 ◽  
Vol 126 (1B) ◽  
pp. 147
Author(s):  
Nguyen Thi Thuy
Keyword(s):  
Electron Microscope ◽  
Solid State ◽  
Room Temperature ◽  
Unit Cell Volume ◽  
Single Phase ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Scanning Electron

<p><strong>Abstract: </strong>LaFeO<sub>3</sub> system with doped Ti, Co, Cu was manufactured by solid state reaction method, it was sintered at 1250<sup>0</sup>C and 1290<sup>0</sup>C in 10 hours with a heating rate of 3<sup>0</sup>C/min. Using X-ray diffraction and Scanning Electron Microscope (SEM) to examine the structure, it reveals that samples are single-phase and orthogonal-perovskite structure describing by the Pnma space group, the unit cell volume of the samples increases when Ti, Co, Cu are doped to replace ion Fe<sup>+3</sup>. The size of particle increase while raising the temperature of sintering. Measuring the resistance which depends on temperature between the room temperature and 1000K, it can be seen that when doping Co, Cu with the nominal component La(Fe<sub>0,2</sub>Co<sub>0,2</sub>Ti<sub>0,6</sub>)O<sub>3</sub> and La(Fe<sub>0,4</sub>Cu<sub>0,1</sub>Ti<sub>0,5</sub>)O<sub>3 </sub>, the conductivity of samples increases respectively. Especially, the conductivity of Cu doped sample is higher than two other samples, and reach the highest conductivity at about 900<sup>0</sup>C, Seebeck coefficient S of La(Fe<sub>0.6</sub>Ti<sub>0.4</sub>)O<sub>3</sub> can be change from positive to negative at the temperature of around 700<sup>0</sup>C.</p>

scholarly journals Zn-Mn-O: Ferromagnet at room temperature

2007 ◽  
Vol 61 (3) ◽  
pp. 147-151
Author(s):  
Dusan Milivojevic ◽  
Jovan Blanusa ◽  
Vojislav Spasojevic ◽  
Vladan Kusigerski ◽  
Branka Babic-Stojic
Keyword(s):  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Diffraction Method ◽  
Solid State Reaction Method ◽  
Paramagnetic Resonance ◽  
Reaction Method ◽  
X Ray ◽  
Electron Paramagnetic ◽  
Mn Oxides ◽  
Thermally Treated

Semiconductor Zn-Mn-O crystallites were synthesized by a solid state reaction method starting from the thermal decomposition of the appropriate oxalates. Samples were thermally treated in air at temperatures ranging from 400 to 900?C. The nominal concentrations of manganese werex = 0.01, 0.02, 0.04 and 0.10. The samples were investigated by the X-ray powder diffraction method, magnetization measurements and by electron paramagnetic resonance. X-ray diffractgrams show a dominant wurtzite structure of Zn-Mn-O. Room temperature ferromagnetism was observed in Zn-Mn-O samples with manganese concentrations x ? 0.04, thermally treated at low temperature (500?C). The saturation magnetiza?tion for the sample with x = 0.01 was 0.05 ?B/Mn. The room temperature ferromagnetism seems to be due to the diffusion of Zn into the Mn-oxides grains.

Sign in / Sign up

Export Citation Format

Share Document