Recovery of electron-irradiated zirconium at low temperatures

1968 ◽  
Vol 46 (5) ◽  
pp. 321-324 ◽  
Author(s):  
H. H. Neely
Keyword(s):  
Electrical Resistivity ◽  
Low Temperature ◽  
Electron Irradiation ◽  
Low Temperatures ◽  
Stage I ◽  
Resistivity Change ◽  
Low Oxygen ◽  
Defect Migration ◽  
Pair Annihilation ◽  
Temperature Recovery

The low-temperature recovery of the electrical resistivity of polycrystalline zirconium was measured after electron irradiation below 8 °K. The material used in this irradiation was the same low oxygen material (0.015 at.%) used by Swanson to study recovery after deformation at 4.2 °K. Substage IB was found to be only of the order of 4% of the irradiation-induced resistivity change, compared to ~6% observed by Swanson after deformation. Stage I (4.2 to 160 °K) in Zr contains six substages, while stage II (160 to 310 °K) contains only one substage after electron irradiation. While no study of kinetics was made, it seems likely that close pair-annihilation processes are responsible for the recovery spectrum below 118 °K and that longer-range defect migration occurs in the neighborhood of 140 °K.

scholarly journals On the electrical resistivity of electrolytic bismuth at low temperature, and in magnetic fields

1897 ◽  
Vol 60 (359-367) ◽  
pp. 425-432 ◽  
Keyword(s):  
Electrical Resistivity ◽  
Low Temperature ◽  
Magnetic Fields ◽  
Electrical Resistance ◽  
Low Temperatures ◽  
Royal Society ◽  
Pole Piece ◽  
Interpolar Distance ◽  
Pure Bismuth ◽  
Transverse Magnetisation

In a previous communication to the Royal Society we have pointed out the behaviour of electrolytically prepared bismuth when cooled to very low temperatures, and at the same time subjected to transverse magnetisation. During the last summer we have extended these observations, and completed them, as far as possible, by making measurements of the electrical resistance of a wire of pure bismuth, placed transversely to the direction of the field of an electromagnet, and at the same time subjected to the low temperature obtained by the use of liquid air. Sir David Salomons was so kind as to lend us for some time his large electromagnet, which, in addition to giving a powerful field, is provided with the means of easily altering the interpolar distance of the pole pieces, and also for changing from one form of pole piece to another.

Primary Defects in n-Type Irradiated Germanium: A First-Principles Investigation

2007 ◽  
Vol 131-133 ◽  
pp. 253-258 ◽  
Author(s):  
A. Carvalho ◽  
R. Jones ◽  
C. Janke ◽  
Sven Öberg ◽  
Patrick R. Briddon
Keyword(s):  
Low Temperature ◽  
Point Defects ◽  
Electron Irradiation ◽  
First Principles ◽  
Low Temperatures ◽  
Damage Evolution ◽  
Room Temperature ◽  
Temperature Electron ◽  
Conductivity Loss

The properties of point defects introduced by low temperature electron irradiation of germanium are investigated by first-principles modeling. Close Frenkel pairs, including the metastable fourfold coordinated defect, are modelled and their stability is discussed. It is found that damage evolution upon annealing below room temperature can be consistently explained with the formation of correlated interstitial-vacancy pairs if the charge-dependent properties of the vacancy and self-interstitial are taken into account. We propose that Frenkel pairs can trap up to two electrons and are responsible for conductivity loss in n-type Ge at low temperatures.

LOW TEMPERATURE RECOVERY OF DEFORMED ZIRCONIUM

1966 ◽  
Vol 44 (12) ◽  
pp. 3241-3257 ◽  
Author(s):  
M. L. Swanson
Keyword(s):  
Electrical Resistivity ◽  
Low Temperature ◽  
Oxygen Atom ◽  
Activation Energies ◽  
Recovery Stage ◽  
First Order ◽  
Temperature Recovery

The low-temperature recovery of the electrical resistivity increment Δρ0 produced by deformation of polycrystalline Zr at 4.2 °K was investigated. Particular attention was given to the large recovery stage occurring between 30° and 40 °K, which amounted to 30% of Δρ0 for Zr containing ~0.070 at. % oxygen, but only 6% of Δρ0 for Zr containing ~0.015 at. % oxygen. By means of isochronal and isothermal anneals, this recovery stage was shown to be due to several first-order annealing processes (with activation energies between 0.105 and 0.125 eV), which were attributed to defect-oxygen atom interactions. Additional recovery peaks were observed at 190 °K and 310 °K only for the lower purity Zr, whose recovery to 360 °K was approximately 80%.

scholarly journals Early Age Hydration Characteristics of Calcium Sulphoaluminate Cement Mortar Cured at a Temperature Range from −10 to 20°C

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Zhongyu Chen ◽  
Jianhong Fang ◽  
Feng Ming ◽  
Yuhang Liu
Keyword(s):  
Compressive Strength ◽  
Electrical Resistivity ◽  
Low Temperature ◽  
Induction Period ◽  
Low Temperatures ◽  
Curing Temperature ◽  
Hydration Process ◽  
Strength Increase ◽  
Calcium Sulphoaluminate ◽  
Hydration Characteristics

With the increasing number of infrastructures constructed in marine and cold regions, research on and applications of calcium sulphoaluminate (CSA) cement have been flourished, but the hydration process of CSA at low temperature has not been systematically investigated. To characterize the influence of low temperature on the hydration characteristics, freshly mixed CSA mortars were cured at −10, −5, 0, 5, and 20°C, respectively. The hydration process was investigated by electrical resistivity, compressive strength, and microstructure analyses. Results show that the hydration process (especially the induction period) is lengthened by low curing temperature. Both the electrical resistivity and compressive strength increase with an increase in the curing temperature. The compressive strength was reduced at a low curing temperature. Among these five curing temperatures, 5°C is the optimal curing temperature. Low temperatures do not change the kinds of hydrates, but reduce their amount. The scanning electron microscopy results illustrate that fewer hydrates fill the pores in specimens cured at low temperatures, while more hydrates form at higher temperatures. Moreover, low curing temperature contributes to the formation of coarse ettringite crystals. For the cement used at low temperature, the induction period should be reduced by adjusting the calcining process and composition proportion.

Sign in / Sign up

Export Citation Format

Share Document