Determination of the ideal resistivity and of the deviation from Matthiessen's rule in gold below 40 K

1979 ◽  
Vol 57 (9) ◽  
pp. 1579-1588 ◽  
Author(s):  
J. F. Kos ◽  
R. J. Barton
1973 ◽  
Vol 51 (15) ◽  
pp. 1602-1618 ◽  
Author(s):  
J. F. Kos

Measurements of the temperature dependence of the electrical resistivity of strained and annealed samples of very pure Ag between 1.4 and 295 °K have permitted the unambiguous and precise determination of the ideal resistivity ρi and of the deviation from Matthiessen's rule ρM. Between 12 and 23 °K, ρi varies as[Formula: see text]and has been attributed to normal and umklapp scattering. Below 10 °K an additional term with a T3.86 ± 0.08 behavior appears and is attributed to one-step umklapp scattering. For samples with [Formula: see text], [Formula: see text] over the entire temperature range. Below 10 °K the variation of ρM with temperature and with defect concentration is described in terms of the theory of phonon-assisted defect scattering proposed by Klemens.


1975 ◽  
Vol 53 (18) ◽  
pp. 1693-1704 ◽  
Author(s):  
F. W. Kus ◽  
J. P. Carbotte

We have calculated the electrical resistivity of several dilute aluminum based alloys for which experimental data exist on the deviation from Matthiessen's rule(DMR). We take account of the anisotropy in the ideal (pure metal) scattering and its modification on adding impurities. This is a major source of DMR. In addition, we compute the effect of inelastic impurity scattering, interference between impurity and ideal scattering, Debye–Waller factors, and also the effect of mass changes on the alloy resistivity. While some of these mechanisms for DMR can be of importance under specific conditions, they should be included only after the major effect of anisotropy in the ideal scattering has been properly treated.


Author(s):  
David M Hudson

Abstract Freshwater crustaceans are distributed throughout the montane and lowland areas of Colombia, and are therefore a useful indicator group for how aquatic species will respond to climate change. As such, metabolic determination of physiological performance was evaluated for the Colombian pseudothelphusid crab, Neostrengeria macropa (H. Milne Edwards, 1853), over a temperature range inclusive of current temperatures and those predicted by future scenarios in the plateau around the city of Bogotá, namely from 8 °C to 30 °C. The performance results mostly aligned with previous exploratory behavioral determination of the ideal temperature range in the same species, although the metabolism increased at the highest temperature treatments, a point when exploratory behavior declined. These results indicate that this species of montane crab behaviorally compensates for increased thermal stress by decreasing its physical activity, which could have negative predator-prey consequences with changes to community structure as different species undergo climate-mediated geographic range shifts in the region. As this species is endemic to the plateau surrounding Bogotá, it also experiences a number of other stressors to its survival, including infrastructure development and invasive species.


2006 ◽  
Vol 62 (6) ◽  
pp. 1025-1030 ◽  
Author(s):  
Razvan Caracas ◽  
Renata M. Wentzcovitch

Density functional theory is used to determine the possible crystal structure of the CaSiO3 perovskites and their evolution under pressure. The ideal cubic perovskite is considered as a starting point for studying several possible lower-symmetry distorted structures. The theoretical lattice parameters and the atomic coordinates for all the structures are determined, and the results are discussed with respect to experimental data.


1953 ◽  
Vol 6 (1) ◽  
pp. 116 ◽  
Author(s):  
W Boas ◽  
JF Nicholas

Matthiessen's rule has been tested by, determining the slopes of the electrical resistivity-temperature curves for wires of eight common metals and alloys in various states of deformation by wire-drawing. The results show that the slope is independent of deformation, i.e. the rule is true, to within 0�5 per cent. for nickel, copper (two purities), iron, and 80/20 brass, and to within 1 per cent. for aluminium. However, for 75/25 brass and an aluminium bronze, deformations corresponding to logarithmic strains of 2�3 decrease the slopes by 1 and 3 per cent. respectively. As an explanation of this behaviour, it is suggested that deformation causes an increase in the characteristic temperature.


1979 ◽  
Vol 95 (1) ◽  
pp. 203-214 ◽  
Author(s):  
A. Möbius ◽  
F. Goedsche ◽  
D. Elefant ◽  
K.-H. Berthel ◽  
G. Vojta

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