scholarly journals Linear mean free path and quadratic temperature dependence of electron-phonon scattering rate in V82Al18-xFex alloys at low temperature

AIP Advances ◽  
2015 ◽  
Vol 5 (5) ◽  
pp. 057110 ◽  
Author(s):  
R. N. Jana ◽  
S. Sinha ◽  
A. K. Meikap
Keyword(s):  
Low Temperature ◽  
Temperature Dependence ◽  
Free Path ◽  
Phonon Scattering ◽  
Mean Free Path ◽  
Scattering Rate ◽  
Quadratic Temperature ◽  
Electron Phonon Scattering

scholarly journals Thermo-Optical Effects in Plasmonic Metal Nanostructures

2021 ◽  
Vol 66 (2) ◽  
pp. 112
Author(s):  
O.A. Yeshchenko ◽  
A.O. Pinchuk
Keyword(s):  
Surface Plasmon Resonance ◽  
Temperature Dependence ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Laser Heating ◽  
Phonon Scattering ◽  
Red Shift ◽  
Au Nps ◽  
Scattering Rate ◽  
Electron Phonon Scattering

The effects of the temperature on the surface plasmon resonance (SPR) in noble metal nanoparticles at various temperatures ranging from 77 to 1190 K are reviewed. A temperature increase results in an appreciable red shift and leads to a broadening of the SPR in the nanoparticles (NPs). This observed thermal expansion along with an increase in the electron-phonon scattering rate with rising temperature emerge as the dominant physical mechanisms producing the red shift and broadening of the SPR. Strong temperature dependence of surface plasmon enhanced photoluminescence from silver (Ag) and copper (Cu) NPs is observed. The quantum photoluminescence yield of Ag nanoparticles decreases as the temperature increases, due to a decrease in the plasmon enhancement resulting from an increase in the electron-phonon scattering rate. An anomalous temperature dependence of the photoluminescence from Cu nanoparticles was also observed; the quantum yield of photoluminescence increases with the temperature. The interplay between the SPR and the interband transitions plays a critical role in this effect. The surface-plasmon involved laser heating of a dense 2D layer of gold (Au) NPs and of Au NPs in water colloids is also examined. A strong increase in the Au NP temperature occurs, when the laser frequency approaches the SPR. This finding supports the resonant plasmonic character of the laser heating of metal NPs. The sharp blue shift of the surface plasmon resonance in colloidal Au NPs at temperatures exceeding the water boiling point indicates the vapor-bubble formation near the surface of the NPs.

Synthesis and Thermoelectric Properties of NaxCo2O4 Single Crystals

2005 ◽  
Vol 886 ◽  
Author(s):  
Jian He ◽  
Kelvin Aaron ◽  
Edward Abbott ◽  
Joseph Kolis ◽  
Terry M. Tritt
Keyword(s):  
Thermal Conductivity ◽  
High Temperature ◽  
Low Temperature ◽  
Single Crystal ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Free Path ◽  
Mean Free Path ◽  
Flux Method ◽  
Different Types

ABSTRACTSingle crystal NaCo2O4 platelets with sizes up to 6mm were synthesized by the typical high temperature NaCl flux method. The in-plane thermopower α and in-plane resistivity ρ were measured to be ∼100µV/K and 0.3mΩ-cm at 300K, respectively. The in-plane thermal conductivity κ was measured by our custom-designed “PTC” system and found to be ∼5 W-m−1K−1 at 300K, which is 2-3 times larger than the polycrystalline NaCo2O4. The in-plane phonon mean free path lph was estimated to be ∼9.5Å, which is much smaller than the in-plane mean free path of conducting carriers (la∼51Å). A novel low temperature flux method where NaCl/NaOH was used as flux and metallic Co powders as Co source was developed to successfully synthesize Na-deficient NaxCo2O4 crystals with size up to 6mm at low temperature of 550°C. The different temperature dependence in resistivity reveals that two different types of crystals can exist, one is metallic and another is semiconducting. The temperature dependence of the measured k is like that of a disordered solid and the value is found to be ∼7 W-m−1K−1 at 300K.

Quadratic temperature dependence of electron–phonon scattering in disordered V1−xPdx alloys

2005 ◽  
Vol 134 (3) ◽  
pp. 223-228 ◽  
Author(s):  
D. Biswas ◽  
A.K. Meikap ◽  
S.K. Chattopadhyay ◽  
S.K. Chatterjee ◽  
M. Ghosh
Keyword(s):  
Temperature Dependence ◽  
Phonon Scattering ◽  
Quadratic Temperature ◽  
Electron Phonon Scattering

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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