Abstract
An approach previously developed for the calculation of transport coefficients via the Mott relations is applied to the calculation of finite temperature transport properties of disordered alloys - electrical resistivity and the electronic part of thermal conductivity. The coherent-potential approximation is used to treat chemical disorder as well as other sources of electron scattering, i.e., temperature induced magnetic moment fluctuations and lattice vibrations via the alloy analogy model. This approach, which treats all forms of disorder on an equal first-principles footing, is applied to the calculation of transport properties of a series of fcc concentrated solid solutions of the 3d-transition metals Ni, Fe, Co, and Cr. For the nonmagnetic alloys Ni0.8Cr0.2 and Ni0.33Co0.33Cr0.3, the combined effects of chemical disorder and electron-lattice vibrations scattering result in a monotonic increase in the resistivity as a function of temperature from an already large, T=0, residual resistivity. For magnetic Ni0.5Co0.5,Ni0.5Fe0.5, and Ni0.33Fe0.33Co0.33, the residual resistivity of which is small, additional electron scattering from temperature induced magnetic moment fluctuations results in a further rapid increase of the resistivity as a function of temperature. The electronic part of the thermal conductivity in nonmagnetic Ni0.8Cr0.2 and Ni0.33Co0.33Cr0.33 monotonically increases with temperature. This behavior is a result of the competition between a reduction in the conductivity due to electron-lattice vibrations scattering and temperature induced increase in the number of carriers. In the magnetic alloys, electron scattering from magnetic fluctuations leads to an initial rapid decrease in thermal conductivity until this is overcome by an increasing number of carriers at temperatures slightly below the Curie temperature. Similar to the resistivity above TC, the electronic parts of the thermal conductivities are close to each other in all alloys studied.
| Original language | English |
|---|---|
| Article number | 165141 |
| Journal | Physical Review B |
| Volume | 98 |
| Issue number | 16 |
| DOIs | |
| State | Published - Oct 26 2018 |
Funding
This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ). This work was primarily supported as part of the Energy Dissipation to Defect Evolution (EDDE), an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Basic Energy Sciences under Contract Number DE-AC05-00OR22725 (designed the research and performed all theoretical calculations). B.C.S. and A.F.M. were supported by DOE, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division (resistivity measurement). Authors used resources of the National Energy Research Scientific Computing Center, which is supported by the Office of Science of the US Department of Energy. The authors would like to thank A. Strange for critical reading of the paper. S.W., S.M., and H.E. would like to thank the Deutsche Forschungsgemeinschaft for financial support within Priority Program SPP 1538 and the collaborative research centers 689 and 1277 (development of SPR-KKR program package).
| Funders | Funder number |
|---|---|
| U.S. Department of Energy | |
| Office of Science | |
| Basic Energy Sciences | DE-AC05-00OR22725 |
| Division of Materials Sciences and Engineering | |
| Deutsche Forschungsgemeinschaft | SPP 1538 |