Positron beam Doppler broadening spectra and nano-hardness study on helium and hydrogen irradiated RAFM steel

2015 ◽  
Vol 107 ◽  
pp. 19-22 ◽  
Author(s):  
Yongming Wen ◽  
Shuoxue Jin ◽  
Zheng Yang ◽  
Fengfeng Luo ◽  
Zhongcheng Zheng ◽  
...  
Keyword(s):  
Positron Beam ◽  
Doppler Broadening ◽  
Rafm Steel ◽  
Doppler Broadening Spectra

POSITRON INTERACTION IN POLYMERS

2004 ◽  
Vol 19 (23) ◽  
pp. 3951-3959 ◽  
Author(s):  
CORINE BAS ◽  
N. DOMINIQUE ALBÉROLA ◽  
MARIE-FRANCE BARTHE ◽  
JÉRÉMIE De BAERDEMAEKER ◽  
CHARLES DAUWE
Keyword(s):  
Positron Annihilation ◽  
Chemical Structure ◽  
Positron Beam ◽  
Positron Annihilation Spectroscopy ◽  
Hole Size ◽  
Doppler Broadening ◽  
Positron Source ◽  
Positron Annihilation Lifetime ◽  
Doppler Broadening Spectra ◽  
Variable Energy

A series of dense copolyimide membranes was characterized using positron annihilation spectroscopy. The positron annihilation lifetime spectroscopy performed on film with a classical positron source gives informations on the positronium fraction formed and also on the hole size within the film. The Doppler broadening spectra (DBS) of the gamma annihilation rays coupled with a variable energy positron beam allow the microstructural analyses as a function of the film depth. Experimental data were also linked to the chemical structure of the polyimides. It was found that the presence of the fluorine atoms strongly affects the positron annihilitation process and especially the DBS responses.

A Study of Defects in Czochralski-Grown Silicon by Positron Annihilation Spectroscopy

1992 ◽  
Vol 262 ◽  
Author(s):  
S. C. Sharma ◽  
N. Hozhabri ◽  
R. G. Hyer ◽  
T. Hossain ◽  
S. Kim ◽  
...  
Keyword(s):  
Positron Lifetime ◽  
Single Crystal Silicon ◽  
Positron Beam ◽  
Positron Annihilation Spectroscopy ◽  
Doppler Broadening ◽  
Crystal Silicon ◽  
Different Depths ◽  
Positron Lifetime Spectroscopy ◽  
Doppler Broadening Spectra ◽  
Variable Energy

ABSTRACTWe have studied defects in Cz-grown single crystal silicon by utilizing a variable energy positron beam and positron lifetime spectroscopy in conjunction with surface photovoltage measurements. We present results for the depth profile of defects obtained from the Doppler broadening spectra measured by implanting variable energy positrons at different depths ranging from the surface down to ∼ 1 /xm deep. We have also measured positron lifetime spectra at different locations on a wafer and have obtained a radial variation in the density of the vacancy-type defects.

Defect Formation by Ion Implantation in Cz-Si Studied by a Monoenergetic Positron Beam

1992 ◽  
Vol 262 ◽  
Author(s):  
A. Uedono ◽  
Y. Ujihira ◽  
L. Wei ◽  
Y. Tabuki ◽  
S. Tanigawa ◽  
...  
Keyword(s):  
Oxygen Vacancy ◽  
Ion Implantation ◽  
Defect Formation ◽  
Positron Beam ◽  
Low Energy ◽  
Doppler Broadening ◽  
Positron Energy ◽  
Annealing Experiments ◽  
Incident Positron ◽  
Ion Implanted

ABSTRACTVacancy-type defects in ion implanted Si were studied by a monoenergetic positron beam. The depth-distributions of the defects were obtained from measurements of Doppler broadening profiles of the positron annihilation as a function of incident positron energy. The results showed that a size of vacany-clusters introduced by 150-keV P+-ion implantation was found to be smaller than that introduced by 2-MeV P+-ion implantation. This was attributed to an overlap of collision cascades in low-energy (150 keV) ion implanted specimens. From isochronal annealing experiments for 80-keV B+- and 150-keV P+-ion implanted specimens, the defected region was removed by 1200 °C annealing, however, for 2-MeV P+-implanted specimen, two-types of oxygen-vacancy complexes were found to coexist even after 1200 °C annealing.

Isochronal annealing studies on 1.1 MeV Fe ion irradiated RAFM steel using variable energy slow positron beam

2017 ◽  
Author(s):  
Renjith Ramachandran ◽  
C. David ◽  
R. Rajaraman ◽  
S. Abhaya ◽  
B. K. Panigrahi ◽  
...  
Keyword(s):  
Positron Beam ◽  
Isochronal Annealing ◽  
Slow Positron ◽  
Rafm Steel ◽  
Variable Energy

Effect of Fe2O3 Dopant on Electronic Densities and Electrical Properties of ZnO-Based Varistors

2011 ◽  
Vol 415-417 ◽  
pp. 1042-1045
Author(s):  
Wen Deng ◽  
Zhen Quan Lei ◽  
Jiao Ling Zhao ◽  
Yan Qiong Lu ◽  
Ding Kang Xiong
Keyword(s):  
Electrical Properties ◽  
Positron Lifetime ◽  
Nonlinear Coefficient ◽  
Doppler Broadening ◽  
Donor Concentration ◽  
Current Voltage ◽  
Electronic Densities ◽  
Current Voltage Characteristics ◽  
Doppler Broadening Spectra ◽  
Coincidence Doppler Broadening

The effect of the Fe2O3dopant on the electronic densities and the electrical properties has been studied in a ZnO-Bi2O3-SnO2-Co2O3-MnO2-TiO2-Ni2O3-Fe2O3system by the measurements of positron lifetime spectra, coincidence Doppler broadening spectra and current-voltage characteristics. The results show that the 3d electron signal in the spectrum of the varistor increases with the Fe2O3content. The addition of small amount of Fe2O3into the ZnO-based varistor leads to an increase in the donor concentration in the bulk and the defects in the varistor. As the Fe2O3content increased, the threshold voltage (VT) and the nonlinear coefficient (α) of the varistor decreased monotonously.

Positron Annihilation on the Surfaces of Single Crystals of Si, SiO2, Graphite and Cu

2008 ◽  
Vol 607 ◽  
pp. 152-154
Author(s):  
Wen Deng ◽  
Li Yue ◽  
Yu Xia Li ◽  
Xu Xin Cheng ◽  
Ya Qin Wei ◽  
...  
Keyword(s):  
Oxide Film ◽  
Single Crystal ◽  
Single Crystals ◽  
Silicon Oxide ◽  
Positron Beam ◽  
Implantation Energy ◽  
Slow Positron ◽  
Ratio Curve ◽  
Doppler Broadening Spectra ◽  
Beam Technique

Slow positron beam technique has been applied to measure the Doppler broadening spectra for single crystals of Cu, SiO2, graphite, virgin Si, and Si without oxide film. The results show that the Cu ratio curve shows a high peak due to Cu having 10 electrons in the 3d shells. The ratio curve of SiO2 is higher than that of graphite. For the single crystal of Cu, SiO2, graphite, and Si without oxide film, the S (W) parameters decrease (increase) as positron implantation energy increasing. Defects on the surface lead to higher S (lower W) value. For the virgin Si and the thermally grown SiO2-Si samples, the S (W) parameters increase (decrease) as positron implantation energy increasing. It can be due to Si atom at surface, with two dangling bonds, tend to form silicon oxide with O. The W parameter for the single crystal of Cu is relatively high as compared with that of the single crystals of SiO2 and graphite.

scholarly journals Study of Microvoids in High-Rate a-Si:H Using Positron Annihilation

1997 ◽  
Vol 467 ◽  
Author(s):  
X. Zou ◽  
D. P. Webb ◽  
S. H. Lin ◽  
Y. W. Lam ◽  
Y. C. Chan ◽  
...  
Keyword(s):  
Thin Films ◽  
Positron Annihilation ◽  
Surface Region ◽  
Positron Beam ◽  
High Rate ◽  
Doppler Broadening ◽  
Slow Positron ◽  
Depth Profiles ◽  
Vacancy Type Defect ◽  
Low Rate

ABSTRACTIn this paper, we have carried out the positron annihilation measurement on high-rate and low-rate a-Si:H thin films deposited by PECVD. By means of the slow positron beam Doppler-broadening technique, the depth profiles of microvoids in a-Si:H have been determined. We have also studied the vacancy-type defect in the surface region in high-rate grown a-Si:H, making comparison between high-rate and low-rate a-Si:H. By plotting S and W parameters in the (S, W) plane, we have shown that the vacancies in all of the high-rate and low-rate deposited intrinsic samples, and in differently doped low-rate samples are of the same nature.

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