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E. L. Muñoz 1 , D. Richard 1 , A.W. Carbonari 2 , L. A. Errico 1 and M. Rentería 1

PAC study of dynamic hyperfine interactions at 111 In-doped Sc 2 O 3 semiconductor and comparison with ab initio calculations. E. L. Muñoz 1 , D. Richard 1 , A.W. Carbonari 2 , L. A. Errico 1 and M. Rentería 1. 1 Departamento de Física and IFLP (CONICET), La Plata, Argentina,

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E. L. Muñoz 1 , D. Richard 1 , A.W. Carbonari 2 , L. A. Errico 1 and M. Rentería 1

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  1. PAC study of dynamic hyperfine interactions at 111In-doped Sc2O3 semiconductor and comparison with ab initio calculations E. L. Muñoz1, D. Richard1, A.W. Carbonari2, L. A. Errico1 and M. Rentería1 1Departamento de Física and IFLP (CONICET), La Plata, Argentina, 2 Instituto de Pesquisas Energéticas y Nucleares, São Paulo, Brazil

  2. Motivations • The inclusion of impurities in semiconductors have broad significance for the basic and applied research.

  3. Motivations • The inclusion of impurities in semiconductors have broad significance for the basic and applied research. • The experimental characterizations at impurity sites in oxides have a fundamental importance for the evaluation of the ab initio electronic structure calculation predictions of structural and electronic properties in doped systems.

  4. Motivations • The inclusion of impurities in semiconductors have broad significance for the basic and applied research. • The experimental characterizations at impurity sites in oxides have a fundamental importance for the evaluation of the ab initio electronic structure calculation predictions of structural and electronic properties in doped systems. • To correctly understand the underlying physics of the phenomenological model used in perturbation factors it is necessary a theoretical study based in first-principles calculations.

  5. Outline • Studied system • PAC technique • Experimental results • FP-APW+lo calculations • Final remarks

  6. Outline • Studied system • PAC technique • Experimental results • FP-APW+lo calculations • Final remarks

  7. Site D Site C Studied system: Sc2O3 • The Sc2O3 oxide crystallizes in the bixbiyte structure and presents two cation sites: C and D. • The relative abundance is fC /fD=3:1. • The ONN coordination is 6 for both sites. • The D site is axially symmetric and the C site presents high asymmetry.

  8. Studied system: Sc2O3 Site D Site C • The Sc2O3 oxide crystallizes in the bixbiyte structure and presents two cation sites: C and D. • The relative abundance is fC /fD=3:1. • The ONN coordination is 6 for both sites. • The D site is axially symmetric and the C site presents high asymmetry. [1]M. Marezio, Acta Cryst. 20, 723 (1966).

  9. Outline • Studied system • PAC technique • Experimental results • FP-APW+lo calculations • Final remarks

  10. PAC technique Substates m Spin orientation at time t Spin orientation at time t+t

  11. 111Cd probe and sample preparation • Some drops of 111InCl3 were deposited onto a Sc2O3 (99.999% purity) powder pellet. The 111In thermal diffusion was performed in N2 atmosphere (3x108 Pa) in steps from 423 K to 1073 K. The temperature dependence of the EFG was measured in the temperature range 10 K – 900 K.

  12. 111Cd probe and sample preparation Initial stage 3.6 days electron Auger electron K-electron capture Parent isotope used in this work final stage hole estable • Some drops of 111InCl3 were deposited onto a Sc2O3 (99.999% purity) powder pellet. The 111In thermal diffusion was performed in N2 atmosphere (3x108 Pa) in steps from 423 K to 1073 K. The temperature dependence of the EFG was measured in the temperature range 10 K – 900 K.

  13. Dynamic Hyperfine Interactions: Bäverstam and Othaz model r: Abragam and Pound constant g: recovery constant (g-1=g)

  14. EF EF Dynamic Hyperfine Interactions: Bäverstam and Othaz model r: Abragam and Pound constant g: recovery constant (g-1=g) State without electronic holes State with electronic holes

  15. Outline • Studied system • PAC technique • Experimental results • FP-APW+lo calculations • Final remarks

  16. 10 K 100 K 295 K 450 K 650 K 900 K PAC spectra of 111In-doped Sc2O3 The PAC measurements reported by Bartos et al. [A. Bartos, et al., Phys. Lett. A 157, 513 (1991)] do not present results of the HFI parameters vs. T.

  17. Hyperfine Parameters vs. T

  18. Hyperfine Parameters vs. T

  19. Outline • Studied system • PAC technique • Experimental results • FP-APW+lo calculations • Final remarks

  20. FP-APW+lo results in pure Sc2O3

  21. FP-APW+lo results in pure Sc2O3 [1] D. Richard, et al., PRB 82, 035206 (2010). [V33]=1021 V/m2; [dNN]=Å Comparison between APW+lo results using experimental and refined structural parameters

  22. FP-APW+lo results in pure Sc2O3 [1] D. Richard, et al., PRB 82, 035206 (2010). [V33]=1021 V/m2; [dNN]=Å Comparison between APW+lo results using experimental and refined structural parameters

  23. FP-APW+lo results in pure Sc2O3 [1] D. Richard, et al., PRB 82, 035206 (2010). [V33]=1021 V/m2; [dNN]=Å Comparison between APW+lo results using experimental and refined structural parameters

  24. Total Density of States Sc2O3:Cd Neutral cell (Cd0)

  25. Total Density of States Sc2O3:Cd Charged cell (Cd-1) Neutral cell (Cd0)

  26. FP-APW+lo results in Cd-doped Sc2O3 for the unrelaxed and relaxed cell* [V33]=1021 V/m2; [dNN]=Å * Cd-doped Sc2O3 results for the charged cell (Cd-1)

  27. FP-APW+lo results in Cd-doped Sc2O3 for the unrelaxed and relaxed cell* [V33]=1021 V/m2; [dNN]=Å * Cd-doped Sc2O3 results for the charged cell (Cd-1)

  28. FP-APW+lo results in Cd-doped Sc2O3 for the unrelaxed and relaxed cell* [V33]=1021 V/m2; [dNN]=Å * Cd-doped Sc2O3 results for the charged cell (Cd-1)

  29. EFG dependence of the charge state of the Cd impurity These results were checked with the others approximations, LDA and GGA [V33]=1021 V/m2; [dNN]=Å Uncharged cell (Cd+1): 1 removed electron in the cell Neutral cell (Cd0):neutral Cd atom Charged cell (Cd-1): 1 added electron in the cell

  30. EFG dependence of the charge state of the Cd impurity These results were checked with the others approximations, LDA and GGA [V33]=1021 V/m2; [dNN]=Å Uncharged cell (Cd+1): 1 removed electron in the cell Neutral cell (Cd0): neutral Cd atom Charged cell (Cd-1): 1 added electron in the cell

  31. EFG dependence of the charge state of the Cd impurity These results were checked with the others approximations, LDA and GGA [V33]=1021 V/m2; [dNN]=Å Uncharged cell (Cd+1): 1 removed electron in the cell Neutral cell (Cd0): neutral Cd atom Charged cell (Cd-1): 1 added electron in the cell

  32. EFG contributions [Vii]=1021 V/m2

  33. EFG contributions [Vii]=1021 V/m2

  34. EFG contributions [Vii]=1021 V/m2

  35. EFG contributions [Vii]=1021 V/m2

  36. Partial Density of States Cd-4d

  37. Comparison of the results

  38. Comparison of the results

  39. Comparison of the results

  40. Comparison of the results

  41. Comparison of the results • EFG calculated in Cd at site D does not present charge state dependence. • EFG in Cd at site C has a strong charge state dependence. • The Abragam and Pound constant at site C is larger of that of site D in all the temperature range.

  42. Outline • Studied system • PAC technique • Experimental results • FP-APW+lo calculations • Final remarks

  43. Final remarks • From this experimental and ab initio approach, we can conclude that the dynamic interaction observed at Cd impurities located at C sites is more intense than the dynamic interaction at the D site. These behavior of the EFG is attributed to the symmetry of the each site.

  44. Final remarks • From this experimental and ab initio approach, we can conclude that the dynamic interaction observed at Cd impurities located at C sites is more intense than the dynamic interaction at the D site. These behavior of the EFG is attributed to the symmetry of the each site. • We can see that the increase of the EFG dependence with the charge state of the impurity is correlated with an increase of the strength of the dynamic interaction.

  45. Final remarks • From this experimental and ab initio approach, we can conclude that the dynamic interaction observed at Cd impurities located at C sites is more intense than the dynamic interaction at the D site. These behavior of the EFG is attributed to the symmetry of the each site. • We can see that the increase of the EFG dependence with the charge state of the impurity is correlated with an increase of the strength of the dynamic interaction. • Finally, we conclude that an ab initio study can help to understand the underlying physics described by the phenomenological Abragam and Pound model.

  46. Cd- doped In2O3 10 K 475 K 550 K 100 K 150 K 700 K 873 K 400 K

  47. In2O3:Cd – HFIs vs. T

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