THE ELECTRICAL RESISTIVITY OF THERMOMETRICALLY PURE PLATINUM BELOW 11 °K

1967 ◽  
Vol 45 (2) ◽  
pp. 339-354 ◽  
Author(s):  
J. F. Kos ◽  
J. L. G. Lamarche
Keyword(s):  
Electrical Resistivity ◽  
Correction Term ◽  
Residual Resistivity ◽  
Experimental Results ◽  
Band Model ◽  
Temperature Function ◽  
Pure Platinum ◽  
Two Band Model ◽  
The Ideal

A method is developed to obtain an interpolation of the resistance versus temperature function of pure platinum to an accuracy of about 0.01 °K in the range 4.2 to 10 °K, when calibration points below 4.2 and above 10 °K are available for a given sample. A study is made of the application of the two-band model to platinum in the range 1.5 to 11 °K. It is found that the accepted expressions for the ideal resistivity and for the Sondheimer–Wilson correction term do not describe the experimental results satisfactorily. Calculations of the ratio of the residual resistivity of band 2 to that of band 1, and of the ratio of the ideal resistivity of band 2 to that of band 1 indicate that electrons in the second band contribute significantly to the conductivity of platinum. A new expression for the ideal resistivity is proposed to account for the conductivity of the second bands

The electrical resistivity of potassium below 4.2 K

1971 ◽  
Vol 325 (1561) ◽  
pp. 223-249 ◽  
Keyword(s):  
Electrical Resistivity ◽  
Relaxation Time ◽  
Point Defects ◽  
Characteristic Temperature ◽  
Band Model ◽  
Temperature Derivative ◽  
Exponential Form ◽  
Two Band Model ◽  
Umklapp Scattering ◽  
The Ideal

The electrical resistivity of potassium has been measured between 1.2 and 4.2 K for samples with various amounts of impurity, and also for samples which have been deformed and then progressively annealed. After allowing for departures for Matthiessen’s rule (M.r.) an estimate of the ‘ideal’ resistivity can be made: the logarithmic temperature derivative rises from 5.6 at 4.2 K and passes through a maximum of 9.0 at 2.1 K. The Bloch T 5 region does not extend above 1.8 K and does not contribute more than ρ = 20 x 10 -15 T 5 Ω cm to the total ideal resistivity ; at 4 K this T 5 contribution is only about 15% of the total ideal resistivity. The rest of the ideal resistivity between 1.8 and 4.2 K shows an exponential form, as expected from the freezing out of umklapp processes with a characteristic temperature of about 23 K. The measurements agree with recent calculations of Rice & Sham (1970) within about a factor of 2 over a range of 10 5 in resistivity, but they do not allow a clear choice to be made between the different forms of pseudopotential that were discussed. The deviations from M.r. for point defects in potassium appear to be accurately proportional to the ideal resistivity between 2 and 4.2 K, i.e. over a range of 300 in ideal resistivity. The magnitude of the deviations is consistent with galvanomagnetic data analysed according to the two-band model, and it implies that a small group of electrons, about 6% of the total, differs in relaxation time from the rest by a factor of about 3. However, the form of the deviations from M.r. does not seem to be compatible with the two-band model. Dislocations in potassium give a small but characteristic extra deviation from M.r. which may be correlated with umklapp scattering. No evidence was found for the momentum-non-conserving processes which have recently been suggested by Campbell, Caplin & Rizzuto (1971) to be very important in aluminium.

IDEAL RESISTIVITY OF PLATINUM BELOW 20 °K

1967 ◽  
Vol 45 (5) ◽  
pp. 1693-1708 ◽  
Author(s):  
R. J. Berry
Keyword(s):  
Electrical Resistivity ◽  
Impurity Scattering ◽  
Band Model ◽  
Temperature Dependency ◽  
Pure Platinum ◽  
Two Band Model

An improved estimate for the electrical resistivity of ideally pure platinum is derived for the 3–20 °K region from highly accurate measurements on a specimen of thermometric-grade Pt. The two-band model is used to correct for the small, but significant, impurity scattering. The temperature dependency of this "ideal" resistivity function is compared with theory and previous work. Certain discrepancies are noted.

The Electrical Resistivity, Thermal Conductivity, and Thermoelectric Power of Calcium from 30 K to 300 K

1975 ◽  
Vol 53 (5) ◽  
pp. 486-497 ◽  
Author(s):  
J. G. Cook ◽  
M. J. Laubitz ◽  
M. P. Van der Meer
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Band Structure ◽  
Large Deviations ◽  
Transport Properties ◽  
Thermoelectric Power ◽  
Band Model ◽  
Residual Resistance ◽  
Two Samples ◽  
Two Band Model

Data are presented for the thermal and electrical resistivity and thermoelectric power of two samples of Ca (having residual resistance ratios of 10 and 70) between 30 and 300 K. Large deviations from both Matthiessen's rule and the Wiedemann–Franz relationship are observed. The former are tentatively attributed to the presence of two distinct groups of carriers in Ca, and analyzed using the two band model. The latter deviations are interpreted as the effects of band structure. The thermoelectric power of Ca is large. In many respects the transport properties of Ca appear to be similar to those of the transition metals.

HALL EFFECT, THERMOPOWER AND ELECTRICAL RESISTIVITY OF DOPED RuSr2GdCu2O8 SYSTEM

2004 ◽  
Vol 18 (22) ◽  
pp. 3057-3062 ◽  
Author(s):  
G. ILONCA ◽  
F. BEIUSAN ◽  
A. V. POP ◽  
I. MATEI ◽  
E. MACOCIAN ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Hall Effect ◽  
Magnetic Order ◽  
Band Model ◽  
Solid State Reaction Technique ◽  
Sintered Ceramic ◽  
Ceramic Samples ◽  
Sb Doping ◽  
Two Band Model ◽  
Hole Localization

Polycrystalline samples of Ru 1-x Sb x Sr 2 GdCuO 8 doped with Sb , in which magnetic order and superconductivity coexist with T magnetic ≫T c , were prepared by a solid state reaction technique. Lattice parameters, electrical resistivity, Hall and thermopower coefficients measurements on the same sintered ceramic samples are presented. Both Hall effect and thermopower show anomalous decreases below T magnetic which might be explained with a simple two-band model in the RuO 2 layer at T magnetic . It was also observed that the Sb doping reduce the conductivity of the system and the transition temperature decreases with increasing Sb content. This may be due to a distortion of RuO 6 octahedra which is responsible for the increase of hole localization.

High-Temperature Transport Properties of Palladium

1972 ◽  
Vol 50 (3) ◽  
pp. 196-205 ◽  
Author(s):  
M. J. Laubitz ◽  
T. Matsumura
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
High Temperature ◽  
Large Deviations ◽  
Thermoelectric Power ◽  
The Other ◽  
Band Model ◽  
Experimental Systems ◽  
Two Band Model ◽  
Pure Palladium

The thermal conductivity, electrical resistivity, and absolute thermoelectric power of pure palladium have been determined from 90 to 1300 K in two experimental systems of proven reliability. These properties are compared with the sparse available literature data, and show large deviations from them, particularly for the thermal conductivity at high temperatures. The results are also analyzed in terms of a simple two-band model, where one band contains the carriers, and the other acts as a trap into which phonons scatter the carriers. When the recent density of states values of Mueller et al. are used, the model predicts correctly the temperature variation of the electrical resistivity, and reasonably well its observed magnitude and the observed Wiedemann–Franz ratio. However, the model fails badly in respect to the absolute thermoelectric power, predicting values twice as large as the observed ones. Modifications to the model are suggested which may improve the fit between the predicted and observed values.

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.

Opto-mechanical modeling and experimental implementation of an FBG-based piezoelectric bimorph actuator for high voltage sensing applications

2021 ◽  
pp. 1045389X2110282
Author(s):  
Raúl E Jiménez ◽  
José P Montoya ◽  
Rodrigo Acuna Herrera
Keyword(s):  
High Voltage ◽  
Good Accuracy ◽  
Correction Term ◽  
Experimental Results ◽  
Mechanical Modeling ◽  
Piezoelectric Bimorph ◽  
Linear Strain ◽  
Voltage Sensing ◽  
Sensing Applications ◽  
Experimental Implementation

This paper proposes a highly simplified optical voltage sensor by using a piezoelectric bimorph and a Fiber Bragg Grating (FBG) that can be used for high voltage applications with a relatively good accuracy and stability. In this work the theoretical framework for the whole opto-mechanical operation of the optical sensor is detailed and compared to experimental results. In the analysis, a correction term to the electric field is derived to account for the linear strain distribution across the piezoelectric layer improving the designing equations and giving more criteria for future developments. Finally, some experimental results from a laboratory scale optical-based high voltage sensing setup are discussed, and shown to be in excellent agreement with theoretical expected behavior for different voltage magnitudes.

IONIZATION ENERGY AND IMPURITY BAND CONDUCTION OF SHALLOW DONORS IN n-GALLIUM ARSENIDE

1967 ◽  
Vol 45 (1) ◽  
pp. 119-126 ◽  
Author(s):  
J. Basinski ◽  
R. Olivier
Keyword(s):  
Ionization Energy ◽  
Impurity Band ◽  
Shallow Donor ◽  
Band Model ◽  
A Value ◽  
Transition Concentration ◽  
Temperature Electron ◽  
Two Band Model ◽  
Band Conduction ◽  
Made In

Hall effect and resistivity measurements have been made in the temperature range 4.2–360 °K on several samples of n-type GaAs grown under oxygen atmosphere and without any other intentional dopings. The principal shallow donor in this material is considered to be Si. All samples exhibited impurity-band conduction at low temperature. Electron concentrations in the conduction band were calculated, using a two-band model, and then fitted to the usual equation expressing charge neutrality. A value of 2.3 × 10−3 eV was obtained for the ionization energy of the donors, for donor concentration ranging from 5 × 1015 cm−3 to 2 × 1016 cm−3. The conduction in the impurity band was of the hopping type for these concentrations. A value of 3.5 × 1016 cm−3 was obtained for the critical transition concentration of the impurity-band conduction to the metallic type.

scholarly journals Phonon residual resistance of pure crystals

2015 ◽  
Vol 29 (29) ◽  
pp. 1550206
Author(s):  
A. I. Agafonov
Keyword(s):  
Electric Field ◽  
Constant Electric Field ◽  
Finite Thickness ◽  
Mean Free Path ◽  
Residual Resistivity ◽  
Boltzmann Transport ◽  
Residual Resistance ◽  
Temperature Resistance ◽  
Electron Mean Free Path ◽  
The Ideal

In this paper, using the Boltzmann transport equation, we study the zero temperature resistance of perfect metallic crystals of a finite thickness d along which a weak constant electric field E is applied. This resistance, hereinafter referred to as the phonon residual resistance, is caused by the inelastic scattering of electrons heated by the electric field, with emission of long-wave acoustic phonons and is proportional to [Formula: see text]. Consideration is carried out for Cu, Ag and Au perfect crystals with the thickness of about 1 cm, in the fields of the order of 1 mV/cm. Following the Matthiessen rule, the resistance of the pure crystals, the thicknesses of which are much larger than the electron mean free path is represented as the sum of both the impurity and phonon residual resistances. The condition on the thickness and field is found at which the low-temperature resistance of pure crystals does not depend on their purity and is determined by the phonon residual resistivity of the ideal crystals. The calculations are performed for Cu with a purity of at least 99.9999%.

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