Normal metal point contacts

1982 ◽  
Vol 60 (5) ◽  
pp. 740-745 ◽  
Author(s):  
H. van Kempen
Keyword(s):  
Electron Scattering ◽  
Kondo Effect ◽  
Phonon Scattering ◽  
Point Contact ◽  
High Current ◽  
Point Contacts ◽  
Paramagnetic Impurities ◽  
Normal Metals ◽  
Current Densities ◽  
Electron Phonon Scattering

Under conditions of extremely high current densities, deviations from the linear current (I) – voltage (V) relation (Ohm's law) occur in normal metals. One can obtain sufficiently high current densities (of the order of 1010 A/cm2) by applying a voltage to a point contact. The nonlinear Boltzmann equation relates the nonlinearities to the energy dependence of the electron scattering probabilities. It is shown, for example, that d2V/dI2 is proportional to α2(ω)F(ω), where F(ω) is the phonon density of states and α(ω) is the electron–phonon scattering matrix element. In addition other interactions arc studied by this method such as electron–magnon interaction and the interaction of electrons with paramagnetic impurities, the well-known Kondo effect. A double point contact geometry is described which allows electron–surface scattering to be studied.

Is potassium a simple metal?

1982 ◽  
Vol 60 (5) ◽  
pp. 693-702 ◽  
Author(s):  
Nathan Wisbr
Keyword(s):  
Electrical Resistivity ◽  
Electron Scattering ◽  
Phonon Scattering ◽  
Measured Data ◽  
The Other ◽  
Simple Metal ◽  
Temperature Dependent ◽  
Dependent Part ◽  
Simple Behavior ◽  
Electron Phonon Scattering

The temperature-dependent part of the electrical resistivity ρ(T) of a metal consists of the sum of two terms, one term being due to electron–phonon scattering ρcp(T) and the other term being due to electron–electron scattering ρcc(T). One may write[Formula: see text]where θD, is the Debye temperature of the metal and the coefficients C and A give the magnitudes of ρcp(T) and ρcc(T), respectively. For a metal whose electrical resistivity exhibits "simple" behavior, it had been expected that the measured data for ρ(T) would have the following properties. (i) The function f(T/θD) should approach (T/θD) for [Formula: see text]. (ii) The magnitude of the coefficient C should be the same, or nearly so, for all measured samples. (iii) The magnitude of the coefficient A should be the same, or nearly so, for all measured samples.The low-temperature ρexpt(T) data for potassium, which has by now been measured for many samples, exhibit none of these three properties. A discussion will be presented of the reasons for this "non-simple" behavior of ρexpt(T) for potassium.

scholarly journals On the critical current for the charge density wave transport

2002 ◽  
Vol 12 (9) ◽  
pp. 127-128
Author(s):  
A. A. Sinchenko ◽  
S. G. Zybtsev ◽  
I. G. Gorlova ◽  
Yu. I. Latyshev ◽  
V. Ya. Pokrovskii ◽  
...  
Keyword(s):  
Charge Density ◽  
Charge Density Wave ◽  
Density Wave ◽  
Metallic State ◽  
High Current ◽  
Point Contacts ◽  
One Dimensional ◽  
Wave Transport ◽  
Current Densities ◽  
Very High

We report transport measurements under very high current densities j, up to 108 A/cm2, of quasi-one-dimensional charge-density wave (CDW) conductors NbSe3 and TaS3. Above $j_0-10^1$ A/cm2 the point contacts NbSe3-NbSe3 show a sharp singularity, and the TaS3 nanosamples show metallic temperature dependence (positive dR/dn. We interpret both results as an evidence for the suppression of the Peierls gap 2A and development of the metallic state above j0. Possible scenarios of the Peierls state destruction are discussed.

Transport properties of the ferromagnetic metals. II. Nickel

1976 ◽  
Vol 54 (1) ◽  
pp. 92-102 ◽  
Author(s):  
M. J. Laubitz ◽  
T. Matsumura ◽  
P. J. Kelly
Keyword(s):  
Transport Properties ◽  
Electron Scattering ◽  
Phonon Scattering ◽  
Positive Slope ◽  
Ferromagnetic Metals ◽  
Subsequent Publication ◽  
Consistent Group ◽  
Characteristic Features ◽  
Normal Electron ◽  
Electron Phonon Scattering

We present new experimental results for the transport properties of Ni. In comparing these results to previously published values, we show that there exists a consistent group of experimental data which establishes reliably the transport properties of pure Ni from perhaps 30 to 1500 K. In the paramagnetic range (T > 630 K), these properties show three characteristic features: a positive slope of the thermal conductivity (which is equivalent to an electrical resistivity increasing less than linearly with temperature), a large negative thermopower, and a Lorenz function substantially larger than the Sommerfeld value, L0. In attempting to provide an explanation of these features, we have discovered that the model of Mott, wherein the electronic relaxation time is inversely proportional to the density of states, does not appear to be universally valid and, more importantly, that the observed properties cannot be consistently explained if we assume pure electron–phonon scattering. To achieve consistency, at least one other scattering mechanism has to be included, such as normal electron–electron scattering; this will be taken up in detail in a subsequent publication.

scholarly journals Electron-Phonon Scattering in Quantum-Sized Films with the Hyperbolic Pöschl–Teller Potential

2019 ◽  
Vol 64 (4) ◽  
pp. 336
Author(s):  
Kh. A. Gasanov ◽  
J. I. Guseinov ◽  
I. I. Abbasov ◽  
D. J. Askerov ◽  
Kh. O. Sadig
Keyword(s):  
Electron Scattering ◽  
Phonon Scattering ◽  
Transition Probability ◽  
Bulk Crystals ◽  
Dimensional Electron ◽  
Phonon Interaction ◽  
Electron Phonon Interaction ◽  
Dimensional Electron Gas ◽  
Analytical Expressions ◽  
Electron Phonon Scattering

A quantitative theory of electron-phonon interaction in the two-dimensional electron gas in a quantum-sized film with the hyperbolic P¨oschl–Teller confining potential has been developed. Analytical expressions for the transition probability are derived in the case of electron scattering by deformation-induced acoustic, piezoacoustic, and polar optical phonons. The results obtained for various scattering mechanisms in the film are compared with the results obtained for bulk crystals.

TEMPERATURE DEPENDENCE BEHAVIOR OF ELECTRICAL RESISTIVITY IN NOBLE METALS AT LOW TEMPERATURES

2014 ◽  
Vol 5 (3) ◽  
pp. 982-992 ◽  
Author(s):  
M AL-Jalali
Keyword(s):  
Experimental Data ◽  
Electrical Resistivity ◽  
Temperature Dependence ◽  
Concentration Dependence ◽  
Low Temperatures ◽  
Noble Metals ◽  
Phonon Scattering ◽  
Theoretical Models ◽  
Residual Resistivity ◽  
Electron Phonon Scattering

Resistivity temperature – dependence and residual resistivity concentration-dependence in pure noble metals(Cu, Ag, Au) have been studied at low temperatures. Dominations of electron – dislocation and impurity, electron-electron, and electron-phonon scattering were analyzed, contribution of these mechanisms to resistivity were discussed, taking into consideration existing theoretical models and available experimental data, where some new results and ideas were investigated.

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