Electronic structure and magnetic properties of dilute U impurities in metals
| Autor: | S. N. Mishra, S. K. Mohanta, Stefaan Cottenier |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Local density of states
Magnetic moment Condensed matter physics Spin polarization Magnetism 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Electronic Optical and Magnetic Materials 0103 physical sciences Condensed Matter::Strongly Correlated Electrons Density functional theory Local-density approximation 010306 general physics 0210 nano-technology Hyperfine structure Magnetic impurity |
| Zdroj: | Journal of Magnetism and Magnetic Materials. 405:107-116 |
| ISSN: | 0304-8853 |
| DOI: | 10.1016/j.jmmm.2015.12.042 |
| Popis: | The electronic structure and magnetic moment of dilute U impurity in metallic hosts have been calculated from first principles. The calculations have been performed within local density approximation of the density functional theory using Augmented plane wave+local orbital (APW+lo) technique, taking account of spin–orbit coupling and Coulomb correlation through LDA+U approach. We present here our results for the local density of states, magnetic moment and hyperfine field calculated for an isolated U impurity embedded in hosts with sp-, d- and f-type conduction electrons. The results of our systematic study provide a comprehensive insight on the pressure dependence of 5f local magnetism in metallic systems. The unpolarized local density of states (LDOS), analyzed within the frame work of Stoner model suggest the occurrence of local moment for U in sp-elements, noble metals and f-block hosts like La, Ce, Lu and Th. In contrast, U is predicted to be nonmagnetic in most transition metal hosts except in Sc, Ti, Y, Zr, and Hf consistent with the results obtained from spin polarized calculation. The spin and orbital magnetic moments of U computed within the frame of LDA+U formalism show a scaling behavior with lattice compression. We have also computed the spin and orbital hyperfine fields and a detail analysis has been carried out. The host dependent trends for the magnetic moment, hyperfine field and 5f occupation reflect pressure induced change of electronic structure with U valency changing from 3 + to 4 + under lattice compression. In addition, we have made a detailed analysis of the impurity induced host spin polarization suggesting qualitatively different roles of f-band electrons on moment stability. The results presented in this work would be helpful towards understanding magnetism and spin fluctuation in U based alloys. |
| Databáze: | OpenAIRE |
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