Temperature Dependence of Paramagnetic Relaxation at Point Defects in Vitreous Silica

1965 ◽  
Vol 36 (1) ◽  
pp. 124-128 ◽  
Author(s):  
J. G. Castle ◽  
D. W. Feldman
1971 ◽  
Vol 32 (C2) ◽  
pp. C2-151-C2-152
Author(s):  
P. WINTERHAGER ◽  
G. ROTH ◽  
R. JOHN ◽  
K. LÜCKE

1978 ◽  
Vol 21 (85) ◽  
pp. 115-122
Author(s):  
J. H. Bilgram ◽  
H. Gränicher

AbstractThe interaction of point detects in ice has been neglected for a long time. Experimental data obtained from dielectric measurements on HF-doped crystals stimulated a new evaluation of the possibility of an interaction between Bjerrum defects and ions. In a previous paper it has been shown that this leads us to assume the existence of aggregates of Bjerrum defects and ions. In this paper these aggregates and Bjerrum defects are used to explain the dielectric properties of ice, especially the temperature dependence of the product of the high and low frequency conductivity σ0σ∞.The interaction of Bjerrum defects and impurity molecules leads to a dependence of the concentration of frenkel pairs on Bjerrum-defect concentration. At HF concentrations above the native Bjerrum-defect concentration the formation of a Frenkel pair is enhanced. This leads to the fast out-diffusion which has been studied in highly doped crystals by means of NMR techniques.


2005 ◽  
Vol 44 (10) ◽  
pp. 7550-7551 ◽  
Author(s):  
Nobu Kuzuu ◽  
Ken Nagai ◽  
Mitsuya Tanaka ◽  
Yoshinori Tamai

2017 ◽  
Vol 726 ◽  
pp. 153-158
Author(s):  
Ai Bing Du ◽  
Zhi Xue Qu ◽  
Xi Ping Su ◽  
Xiao Xiao

The thermal conduction behavior of the neutron absorbing ceramic boron carbide in the initial stage of the irradiation was analyzed and a classical thermal conduction model was used to estimate the variation of the thermal conductivity in this paper. The calculated thermal conductivity using the model shows a large degration in the initial stage of irradiation. As the burnup increases, the thermal conductivity turns to be free of temperature dependence. These calculated results are consistent well with the expermental data of thermal conductivity of the irradiated boron carbide, which may suggest that the variation of the thermal conductivity of boron carbide is predominantly determined by the point defects scattering in the initial stage of irradiation.


When samples of α plutonium are stored at low temperatures their resistivities increase owing to the accumulation of defects produced by the radioactive disintegration of the nuclei. Isochronal annealing experiments have been performed on α plutonium which show that this additional resistivity recovers in two distinct stages centred at ca . 75 and 150 °K respectively. In δ stabilized plutonium the first annealing stage is more pronounced and occurs at lower temperatures, the values of which are dependent on the concentration of aluminium used to stabilize the δ phase. Isochronal annealing experiments have also been performed on heavily damaged samples of α plutonium and yield further information on the anomalous temperature dependence of the resistivity changes brought about by self irradiation at low temperatures. The correlation between the observed resistivity changes and corresponding changes in the concentration of point defects is discussed.


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