A First-Principles Calculation of the Resistivity and Thermopower in Strong-Scattering Alloys

1988 ◽  
Vol 141 ◽  
Author(s):  
Randall H. Brown ◽  
Philip B. Allen ◽  
Donald M. Nicholson ◽  
William H. Butler
Keyword(s):  
First Principles ◽  
Statistical Error ◽  
Mean Free Path ◽  
Localized States ◽  
First Principles Calculation ◽  
Disordered Alloys ◽  
Alloy Disorder ◽  
Electron Mean Free Path ◽  
Strong Scattering ◽  
Temperature Resistivity

AbstractWe investigate the concentration and short-range order dependence of the zero-temperature resistivity and thermopower for substitutionally disordered alloys from a first-principles approach. The alloy disorder is simulated by calculating the electronic structure of a large supercell (typically 200–250 atoms) with periodic boundary conditions. For the strong-scattering alloys we consider, the electron mean-free path is much less than the supercell dimension, causing artificial effects of periodicity to be negligible. In spite of strong scattering, there is no evidence for localized states near EF. The resistivity and thermopower are averaged over several configurations resulting in statistical error bounds of approximately ±10%. The concentration-dependent resistivity of substitutional V1−xAlx alloys agree well with Korringa-Kohn-Rostoker coherent potential approximation (KKR CPA) calculations. This confirms the accuracy of KKR CPA theory.

First Principles Calculation of Residual Resistivity

1991 ◽  
Vol 253 ◽  
Author(s):  
D. M. Nicholson ◽  
R. H. Brown ◽  
W. H. Butler ◽  
H. Yang ◽  
J. W. Swihart ◽  
...  
Keyword(s):  
Multiple Scattering ◽  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Mean Free Path ◽  
Residual Resistivity ◽  
First Principles Calculation ◽  
Functional Theory ◽  
Disordered Alloys ◽  
Random Alloys

ABSTRACTThe list of physical properties which are important in the design of materials and which are routinely calculated from first principles within the local density approximation to density functional theory is continually growing. In this paper we discuss the application of multiple scattering theory to the calculation of the residual resistivity of disordered alloys. Progress has been made on two fronts. First, the coherent potential approximation for the resistivity, which sums to all orders a limited set of multiple scattering diagrams, has given resistivities in agreement with experiment for alloys where the site occupation is roughly random. Second, the linearized KKR was used to evaluate the Kubo formula for several large configurations of atoms and obtain the resistivity with all multiple scattering paths included. This method is not limited to random alloys, but can be applied to short range ordered and amorphous alloys provided the resistivity is high enough to limit the mean free path to a single unit cell.

scholarly journals First-principles simulation of electron mean-free-path spectra and thermoelectric properties in silicon

2015 ◽  
Vol 109 (5) ◽  
pp. 57006 ◽  
Author(s):  
Bo Qiu ◽  
Zhiting Tian ◽  
Ajit Vallabhaneni ◽  
Bolin Liao ◽  
Jonathan M. Mendoza ◽  
...  
Keyword(s):  
Free Path ◽  
Thermoelectric Properties ◽  
First Principles ◽  
Mean Free Path ◽  
Electron Mean Free Path

Intrinsic Thermal Conductivity of Wurtzite AlxGa1-xN, InxGa1-xN and InxAl1-xN From First-Principles Calculation

2015 ◽  
Author(s):  
Jinlong Ma ◽  
Baoling Huang ◽  
Wu Li ◽  
Xiaobing Luo
Keyword(s):  
Thermal Conductivity ◽  
First Principles ◽  
Room Temperature ◽  
Mean Free Path ◽  
First Principles Calculation ◽  
First Principles Calculations ◽  
Out Of Plane ◽  
Pure Compounds ◽  
Crystal Model ◽  
Thermal Conductivities

The thermal conductivities of the alloys of wurtzite AlN, GaN and InN are usually analyzed with the virtual crystal model based on the values of the constituent compounds. However, latest experiments and calculations reveal that the thermal conductivity of wurtzite InN is about three times larger than the previously used value. Thus it is necessary to reanalyze the thermal conductivities of these alloys. In this work, the intrinsic thermal conductivities of AlxGa1−xN, InxGa1−xN and InxAl1−xN are calculated with first-principles calculations along with the virtual crystal treatment. It is found that the thermal conductivities of these alloys are strongly suppressed even after a small amount of alloying. For instance, the in-plane and out-of-plane thermal conductivities of In0.99Ga0.01 N are 66 Wm−1K−1 and 76 Wm−1K−1 respectively, while they are 40 Wm−1K−1 and 48 Wm−1 K−1 for In0.99Al0.01 N, compared with the corresponding values of 130 Wm−1 K−1 and 145 Wm−1 K−1 for bulk wurtzite InN. When the fraction x varies from 0.2 to 0.8, the thermal conductivities of the alloys do not change much. Additionally, the distribution of mean free path indicates that the size effect can persist up to 10μm for both pure compounds and their alloys at room temperature.

scholarly journals First-Principles Density Functional Theory Study of Modified Germanene-Based Electrode Materials

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 103
Author(s):  
Xue Si ◽  
Weihan She ◽  
Qiang Xu ◽  
Guangmin Yang ◽  
Zhuo Li ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
First Principles ◽  
Density Functional ◽  
Electrode Materials ◽  
Layer Structure ◽  
Localized States ◽  
First Principles Calculation ◽  
Quantum Capacitance ◽  
Multilayered Structures ◽  
Functional Theory

Germanene, with a wrinkled atomic layer structure and high specific surface area, showed high potential as an electrode material for supercapacitors. According to the first-principles calculation based on Density Functional Theory, the quantum capacitance of germanene could be significantly improved by introducing doping/co-doping, vacancy defects and multilayered structures. The quantum capacitance obtained enhancement as a result of the generation of localized states near the Dirac point and/or the movement of the Fermi level induced by doping and/or defects. In addition, it was found that the quantum capacitance enhanced monotonically with the increase of the defect concentration.

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