Observation of intrinsic emission in β-BiNbO4 available for excitation of both UV light and high energy irradiation

2016 ◽  
Vol 18 (34) ◽  
pp. 23702-23708 ◽  
Author(s):  
Ruijin Yu ◽  
Aiping Fan ◽  
Maosen Yuan ◽  
Tianbao Li ◽  
Jinyi Wang

β-BiNbO4 shows photoluminescence and scintillation emission at room temperature. The excitation is from optical transitions from NbO67− groups and 6s(Bi)–4d(Nb) MMCT states; the intrinsic emission is from 3P1 → 1S0 transitions of Bi3+ ions under UV light and X-ray excitation.

1972 ◽  
Vol 27 (11) ◽  
pp. 1289-1293 ◽  
Author(s):  
W. G. Filby ◽  
K. Günther

The nature and properties of radicals produced by the action of electron and γ-radiation on adamantane have been investigated. Radicals produced by irradiation at 77°K are stable to around room temperature, while irradiation at the latter temperature yields well resolved spectra of species stable to about 130°C. The significance of the latter, assigned as the 1-adamantyl radical, in the formation of trapped radicals is discussed.


2002 ◽  
Vol 16 (06n07) ◽  
pp. 1047-1051
Author(s):  
JIANPING MA ◽  
ZHIMING CHEN ◽  
GANG LU ◽  
MINGBIN YU ◽  
LIANMAO HANG ◽  
...  

Intense photoluminescence (PL) has been observed at room temperature from the polycrystalline SiC samples prepared from carbon-saturated Si melt at a temperature ranging from 1500 to 1650°C. Composition and structure of the samples have been confirmed by means of X-ray photoelectron spectroscopy, X-ray diffraction and scanning electron microscopy. PL measurements with 325 nm UV light excitation revealed that the room temperature PL spectrum of the samples consists of 3 luminescent bands, the peak energies of which are 2.38 eV, 2.77 eV and 3.06 eV, respectively. The 2.38 eV band is much stronger than the others. It is suggested that some extrinsic PL mechanisms associated with defect or interface states would be responsible to the intensive PL observed at room temperature.


2011 ◽  
Vol 479 ◽  
pp. 54-61 ◽  
Author(s):  
Fei Wang ◽  
Ya Ping Wang

Microstructure evolution of high energy milled Al-50wt%Si alloy during heat treatment at different temperature was studied. Scanning electron microscope (SEM) and X-ray diffraction (XRD) results show that the size of the alloy powders decreased with increasing milling time. The observable coarsening of Si particles was not seen below 730°C in the high energy milled alloy, whereas, for the alloy prepared by mixed Al and Si powders, the grain growth occurred at 660°C. The activation energy for the grain growth of Si particles in the high energy milled alloy was determined as about 244 kJ/mol by the differential scanning calorimetry (DSC) data analysis. The size of Si particles in the hot pressed Al-50wt%Si alloy prepared by high energy milled powders was 5-30 m at 700°C, which was significantly reduced compared to that of the original Si powders. Thermal diffusivity of the hot pressed Al-50wt%Si alloy was 55 mm2/s at room temperature which was obtained by laser method.


2017 ◽  
Vol 154 (3) ◽  
pp. 121 ◽  
Author(s):  
V. Bourrier ◽  
J. de Wit ◽  
E. Bolmont ◽  
V. Stamenković ◽  
P. J. Wheatley ◽  
...  

2019 ◽  
Vol 201 (1) ◽  
pp. 12-22
Author(s):  
Chin-Chi Cheng

Poling process is one of the widely used strategies to enhance the film properties during the manufacturing processes of ceramic film. A lab-made PbZrxTi1-xO3 (PZT) film by spin-coating on Ti substrate is presented. After heating treatments, the fabricated film was passed corona poling under ultraviolent (UV) light of various power. The characteristics of the PZT film have been evaluated by several instruments, such as X-ray diffractometer (XRD), scanning electron microscopy (SEM) and impedance analyzer. The results indicated that UV light would affect the orientation of crystallization, microstructure and grain size of PZT film surface during poling process under room temperature.


Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 273 ◽  
Author(s):  
Suman ◽  
Surjeet Chahal ◽  
Ashok Kumar ◽  
Parmod Kumar

Zinc (Zn) doped hematite (α-Fe2O3) nanoparticles with varying concentrations (pure, 2%, 4% and 6%) were synthesized via sol-gel method. The influence of divalent Zn ions on structural, optical and dielectric behavior of hematite were studied. X-ray diffraction (XRD) pattern of synthesized samples were indexed to rhombohedral R3c space group of hematite with 14–21 nm crystallite size. The lattice parameter (a and c) values increase upto Zn 4% and decrease afterwards. The surface morphology of prepared nanoparticles were explored using transmission electron microscopy (TEM). The band gap measured from Tauc’s plot, using UV-Vis spectroscopy, showed reduction in its values upto Zn 4% and the reverse trend was obtained in higher concentrations. The dielectric properties of pure and Zn doped hematite were investigated at room temperature and followed the same trends as that of XRD parameters and band gap. Photocatalytic properties of nanoparticles were performed for hazardous Rose bengal dye and showed effective degradation in the presence of UV light. Hence, Zn2+ doped hematite can be considered as an efficient material for the potential applications in the domain of photocatalysis and also higher value of dielectric constant at room temperature makes them applicable in high energy storage devices.


Author(s):  
Stefano Grillanda ◽  
Vivek Singh ◽  
Vivek Raghunathan ◽  
Shuttha Shutthanandan ◽  
Francesco Morichetti ◽  
...  

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