Bizmut adsorbe eden çinko oksit nanotellerin manyetik işlevselleşmesi

Abstract

Bizmut atomunun çinko oksit nanotelinin yüzeyine adsorpsiyonu Hubbard U düzeltmesi içeren yoğunluk-fonksiyonel hesaplamaları ile incelenmiştir. Birçok ekatom konfigürasyonları için geometri optimizasyonları gerçekleştirilerek, adsorpsiyon enerjileri ve manyetik momentler hesap edilmiştir. En düşük enerjili ekatom konfigürasyonu böylece belirlenmiştir. Bu konfigürasyonun bir eğik manyetik momente sahip olduğu bulunmuştur. Bu, manyetik moment vektörünün yönünün harici bir manyetik alan uygulanarak kontrol edilebileceği anlamına gelmektedir. Bant yapısı hesaplamaları bu öz manyetik momentin varlığının alt iletim bandı durumlarında değiş-tokuş yarılmasına neden olduğunu ortaya koymaktadır. Bu bulgular bizmut adsorpsiyonunun çinko oksit nanotellerinin manyetik işlevselleşmesine neden olduğunu göstermektedir.

Keywords

• Eğik manyetik moment,Yoğunluk fonksiyonel teorisi,Çinko oksit,Nanotel,Adsorpsiyon,Bizmut

Magnetic functionalization of bismuth-adsorbing zinc oxide nanowires

Abstract

The adsorption of bismuth atom on the surface of zinc oxide nanowires is investigated by carrying out density-functional calculations with Hubbard U correction. Geometry optimizations are performed for a number of adatom configurations, and the adsorption energies and magnetic moments are calculated. The lowest-energy adatom configuration is thus determined. It is found that this configuration possess a canted magnetic moment. This means that the orientation of the magnetic moment vector can be controlled by applying an external magnetic field. Band structure calculations reveal that the existence of this intrinsic magnetic moment causes a exchange splitting of the lower conduction band states. These findings show that the adsorption of bismuth leads to magnetic functionalization of zinc oxide nanowires.

Keywords

• Canted magnetic moment,Density functional theory,Zinc oxide,Nanowire,Adsorption,Bismuth

References

1. C.-L. Hsu, S.-J. Chang, «Doped ZnO 1D Nanostructures: Synthesis, Properties, and Photodetector Application,» Small, cilt 10, p. 4562, 2014
2. G. Li, A. Sundararajan, A. Mouti, et al., «Synthesis and characterization of p-n homojunction-containing zinc oxide nanowires,» Nanoscale, cilt 5, p. 2259, 2013
3. M. J. Spencer, «Gas sensing applications of 1D-nanostructured zinc oxide: Insights from density functional theory calculations,» Prog. Mater Sci., cilt 57, p. 437, (2012
4. O. Lupan, T. Pauport, T. Le Bahers, et al., «Wavelength-Emission Tuning of ZnO Nanowire-Based Light-Emitting Diodes by Cu Doping: Experimental and Computational Insights,» Adv. Funct. Mater., cilt 21, p. 3564, 2011.
5. M.-P. Lu, J. Song, M.-Y. Lu, et al., «Piezoelectric Nanogenerator Using p-Type ZnO Nanowire Arrays,» Nano Lett., cilt 9, no. 3, p. 1223–1227, 2009
6. G.-D. Yuan, W.-J. Zhang, J.-S. Jie et al., «Tunable n-Type Conductivity and Transport Properties of Ga-doped ZnO Nanowire Arrays,» Adv. Mater., cilt 20, p. 168, 2008
7. Y. Huang, Y. Zhang, Y. Gu, et al., «Field Emission of a Single In-Doped ZnO Nanowire,» J. Phys. Chem. C, cilt 111, no. 26, p. 9039–9043, 2007
8. Y. Q. Chang, D. B. Wang, X. H. Luo, et al., «Synthesis, optical, and magnetic properties of diluted magnetic semiconductor Zn 1− x Mn x O nanowires via vapor phase growth,» Appl. Phys. Lett., cilt 83, pp. 4020-4022, 2003.

9. J. B. Cui, U. J. Gibson, «Electrodeposition and room temperature ferromagnetic anisotropy of Co and Ni-doped ZnO nanowire arrays,» Appl. Phys. Lett., cilt 87, p. 133108, 2005
10. J. Segura-Ruiz, G. Martinez-Criado, M. H. Chu, et al., «Nano-X-ray Absorption Spectroscopy of Single Co-Implanted ZnO Nanowires,» Nano Lett., cilt 11, p. 5322, 2011
11. J. Iqbal, X. Liu, H. Zhu, et al., «Trapping of Ce electrons in band gap and room temperature ferromagnetism of Ce4+Ce4+ doped ZnO nanowires,» J. Appl. Phys., cilt 106, p. 083515, 2009
12. X. Ma, «The magnetic properties of Gd doped ZnO nanowires,» Thin Solid Films, cilt 520, p. 5752, 2012
13. M. Aras, S. Güler-Kılıç, Ç. Kılıç, «Doping-induced spin-orbit splitting in Bi-doped ZnO nanowires,» Phys. Rev. B., 2017 to be published.
14. G. Kresse and J. Furthmüller, «Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set,» Phys. Rev. B, cilt 54, p. 11169, 1996.
15. S. L. Dudarev, G. A. Botton, S. Y. Savrasov, et al., «Electron-energy-loss spectra and the structural stability of nickel oxide:  An LSDA+U study,» Phys. Rev. B, cilt 57, p. 1505, 1998.
16. J. P. Perdew, K. Burke, and M. Ernzerhof, «Generalized Gradient Approximation Made Simple,» Phys. Rev. Lett., cilt 77, p. 3865, 1996
17. Ç. Kılıç, M. Aras, S. Güler-Kılıç, «Computational studies of bismuth-doped zinc oxide nanowires,» Low- Dimensional and Nanostructured Materials and Devices: Properties, Synthesis, Characterization, Modelling and Applications, Cham, Springer International Publishing, 2016, pp. 401-421.
18. D. Hobbs, G. Kresse, J. Hafner, «Fully unconstrained noncollinear magnetism within the projector augmented-wave method,» Phys. Rev. B, cilt 62, p. 11556, 2000.
19. M. Marsman, J. Hafner, «Broken symmetries in the crystalline and magnetic structures of γ-iron,» Phys. Rev. B, cilt 66, p. 224409, 2002.
20. J. P. Perdew, K. Burke, and M. Ernzerhof, «Generalized Gradient Approximation Made Simple,» Phys. Rev. Lett., cilt 77, p. 3865, 1996.