scholarly journals NEAR INFRARED – EMITTING Zn2SiO4 POWDERS PRODUCED BY HIGH-ENERGY PLANETARY BALL MILLING TECHNIQUE

2018 ◽  
Vol 56 (1A) ◽  
pp. 212 ◽  
Author(s):  
Le Thi Thao Vien
Keyword(s):  
Ball Milling ◽  
Near Infrared ◽  
Annealing Temperature ◽  
Low Cost ◽  
High Energy ◽  
Infrared Emission ◽  
Host Lattice ◽  
Planetary Ball Milling ◽  
Different Temperatures ◽  
Ball Milling Technique

The near infrared-emitting Zn2SiO4 powders were produced by high-energy planetary ball milling of ZnO and SiO2 powders followed by annealing in air environment and at different temperatures. The surface morphology, crystal structure, chemical composition and optical properties of the obtained samples were investigated by means of field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), Raman spectroscopy and photoluminescence measurements (PL) at room temperature. The analysis indicates the formation of Zn2SiO4 phase with annealing temperature of 1250 oC.°C. The size of Zn2SiO4 nanoparticles depends strongly on annealing temperature. Photoluminescence investigation reveals that the optimal annealing temperature for almost only near-infrared emission (~740 nm) is 1250 oC. The origin of this peak can be attributed to the energy transfer from non-bridging oxygen hole centers (NBOHs) to zinc interstialinterstitial (Zni) and oxygen vacancy (Vo) states in the Zn2SiO4 host lattice. These results demonstrate that we might be able to produce the Zn2SiO4 powders for applications in high CRI white light emitting diodes by a simple and low-cost method. 

Preparation of graphene oxide by dry planetary ball milling process from natural graphite

RSC Advances ◽  
2016 ◽  
Vol 6 (15) ◽  
pp. 12657-12668 ◽  
Author(s):  
Pranita Dash ◽  
Tapan Dash ◽  
Tapan Kumar Rout ◽  
Ashok Kumar Sahu ◽  
Surendra Kumar Biswal ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Ball Milling ◽  
High Energy ◽  
Milling Process ◽  
Graphene Oxides ◽  
Natural Graphite ◽  
Ball Milling Process ◽  
Planetary Ball Milling

Graphene oxides (GO) with different degrees of oxidation have been prepared by an in-house designed horizontal high energy planetary ball milling process.

Investigations on the Structural, Optical and Dielectric Properties of Ball-Milled ZnO–Fe2O3 Nanocomposites

2020 ◽  
Vol 19 (04) ◽  
pp. 1950034
Author(s):  
V. Balachandar ◽  
J. Brijitta ◽  
K. Viswanathan ◽  
R. Sampathkumar
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Ball Milling ◽  
High Energy ◽  
X Ray Diffraction ◽  
Dielectric Constant And Loss ◽  
Energy Ball ◽  
Uv Visible ◽  
Ball Milling Technique ◽  
Xrd Patterns

In this study, ZnO–Fe2O3 nanocomposites were prepared by high-energy ball milling technique and characterized through X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), UV–visible spectroscopy and dielectric spectroscopy. The amount of Fe2O3 in the ZnO–Fe2O3 nanocomposites was varied at the rates of 1[Formula: see text]wt.%, 3[Formula: see text]wt.% and 5[Formula: see text]wt.% in order to investigate its influence on the structural, optical and dielectric properties of the nanocomposites. XRD patterns of nanocomposites revealed no shift in peak positions and hence confirmed the formation of composites after ball milling. Further, it was observed from FESEM analysis that Fe2O3 particles were distributed randomly on the ZnO matrix of the nanocomposites. ZnO–Fe2O3 nanocomposites reveal extended optical absorption in the range of 400–600[Formula: see text]nm from UV studies. The dielectric constant and loss of the nanocomposites decrease exponentially with increase in frequency. The composition and frequency dependences of the dielectric constant, dielectric loss and AC conductivity are explained based on the Maxwell–Wagner effect and Koop’s theory.

Effects of iron impurities in mechanical alloying using steel media

1993 ◽  
Vol 8 (2) ◽  
pp. 239-241 ◽  
Author(s):  
P.J. Yvon ◽  
R.B. Schwarz
Keyword(s):  
Mechanical Alloying ◽  
Ball Milling ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Metastable Phases ◽  
Iron Contamination ◽  
Energy Ball ◽  
Ball Milling Technique

Mechanical alloying, a high-energy ball-milling technique, is now widely used for preparing alloy powders with metastable phases (crystalline or amorphous). The technique, however, may contaminate the powder with material eroded from the vial and milling media. We report on the analysis and effects of iron contamination on Al25Ge75 powders that we prepared by mechanically alloying mixtures of aluminum and germanium powders, using different mechanical alloying apparatuses.

Isosymmetric structural phase transition of the orthorhombic lanthanum gallate structure as a function of temperature determined by Rietveld analysis

CrystEngComm ◽  
2018 ◽  
Vol 20 (37) ◽  
pp. 5562-5569
Author(s):  
Y. Q. Tang ◽  
C. López-Cartes ◽  
M. A. Avilés ◽  
J. M. Córdoba
Keyword(s):  
Phase Transition ◽  
Ball Milling ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Rietveld Analysis ◽  
High Energy ◽  
Lanthanum Gallate ◽  
Air Atmosphere ◽  
Planetary Ball Milling

High energy planetary ball milling has been used to synthesize pseudo-cubic highly-pure LaGaO3 in one hour from its oxide components in an air atmosphere.

scholarly journals Photocatalytic Activity Enhancement of Anatase TiO2by Using TiO

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Zhenrui Chen ◽  
Wei Zhong ◽  
Zhutian Liang ◽  
Weiqian Li ◽  
Guannan He ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Work Function ◽  
Low Cost ◽  
Electron Work Function ◽  
High Energy ◽  
Heterogeneous Structures ◽  
Mean Grain Size ◽  
Energy Ball ◽  
Activity Enhancement ◽  
Ball Milling Technique

We employed high-energy ball-milling technique to fabricate TiO/TiO2heterogeneous nanostructures. XRD proved the existence of TiO/TiO2heterogeneous structures. SEM and HRTEM investigation evidenced that the mean particle size and mean grain size of the as-prepared samples are 23 nm and 13 nm, respectively. UV-Vis spectra exhibited that TiO has enhanced the visible light absorption ofTiO2and has changed theEgofTiO2. UPS examination indicated that the electron work function (EWF) of TiO is higher than that ofTiO2. Photocatalytic degradation experiments revealed that an appropriate TiO content can enhance the photocatalytic activity of pure anataseTiO2. The best photocatalytic activity of TiO/TiO2heterogeneous nanostructures is even better than that of Au-depositedTiO2by keeping high degradation efficiency of 93%. The internal electrical field producing in TiO/TiO2heterogeneous nanostructures was considered to be dominantly responsible for the enhanced photocatalytic activity. Therefore, the substitution of TiO with noble metal inTiO2will be widely used in the future due to its low cost. This study also provides a clear direction of enhancing photocatalytic activity ofTiO2: incorporating a guest compound intoTiO2with an appropriate content if the compound has much higher electron work function than that ofTiO2.

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