Based on the density functional theory, we investigated the electronic structures and magnetic properties of the oxygen adsorption on the defective cubic HfO2 (110) surface. The adsorption capacities of the perfect and defective surfaces follow in the sequence as: oxygen-deficient model >perfect surface >hafnium-deficient model. When the oxygen molecules adsorb on the nonmagnetic perfect HfO2 surface, the system has a local magnetic moment and the antiferromagnetic coupling is more stable. For the defective cubic HfO2 (110) surface, it is found that the oxygen vacancy is more easy to form than the hafnium vacancy by comparing the vacancy formation energy. And the hafnium vacancy could induce a large magnetic moment while the oxygen vacancy alone could not. After adsorption of the oxygen molecule, the nonmagnetic oxygen-deficient HfO2 model is transformed into the magnetic surface. On the contrary, the introduction of adsorbed oxygen molecule causes the magnetic moment of hafnium-deficient HfO2 surface to reduce. Additionally, if the oxygen molecules adsorb on the defective HfO2 (110) surface, the ferromagnetic coupling is energetically favorable.
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This work was supported by the National Natural Science Foundation of China (Grant No. 11604234, 11404236, and 51602214), Special Funds of the National Natural Science Foundation of China (Grant No. 11447189), and Natural Science Foundation of Shanxi (Grant No. 2015021026 and 201601D202010).
Kitchen, D., Richardella, A., Tang, J.M., et al.: Atom-by-atom substitution of Mn in GaAs and visualization of their hole-mediated interactions. Nature 442, 436–439 (2006)ADSCrossRefGoogle Scholar
Sato, K., Katayama-Yoshida, H.: Hyperfine interactions and magnetism of 3d transition-metal-impurities in II-VI and III-v compound-based diluted magnetic semiconductors. Hyperfine Interact. 136, 737–742 (2001)ADSCrossRefGoogle Scholar
Deka, S., Joy, P.A.: Synthesis and magnetic properties of Mn doped ZnO nanowires. Solid State Commun. 142, 190–194 (2007)ADSCrossRefGoogle Scholar
Wang, Y.Q., Yuan, S.L., Liu, L., et al.: Ferromagnetism in Fe-doped ZnO bulk samples. J. Magn. Magn. Mater. 320, 1423–1426 (2008)ADSCrossRefGoogle Scholar
Park, J.H., Kim, M.G., Jang, H.M., et al.: Co-metal clustering as the origin of ferromagnetism in Co-doped ZnO thin films. Appl. Phys. Lett. 84, 1338–1340 (2004)ADSCrossRefGoogle Scholar
Zhou, S., Potzger, K., Von Borany, J., et al.: Crystallographically oriented Co and Ni nanocrystals inside ZnO formed by ion implantation and postannealing. Phys. Rev. B 77, 035209 (2008)ADSCrossRefGoogle Scholar
Kaspar, T.C., Droubay, T., Heald, S.M., et al.: Hidden ferromagnetic secondary phases in cobalt-doped ZnO epitaxial thin films. Phys. Rev. B 77(R), 201303 (2008)ADSCrossRefGoogle Scholar
Venkatesan, M., Fitzgerald, C.B., Coey, J.M.D.: Thin films: unexpected magnetism in a dielectric oxide. Nature 430, 630–630 (2004)ADSCrossRefGoogle Scholar
Demkov, A.A.: Investigating alternative gate dielectrics: a theoretical approach. Phys. Status Solidi B 226, 57–67 (2001)ADSCrossRefGoogle Scholar
Zhao, X., Vanderbilt, D.: First-principles study of structural, vibrational, and lattice dielectric properties of hafnium oxide. Phys. Rev. B 65, 233106 (2002)ADSCrossRefGoogle Scholar
Hong, N.H.: Magnetism due to defects/oxygen vacancies in HfO2 thin films. Phys. Status Solidi (c) 4, 1270–1275 (2007)ADSCrossRefGoogle Scholar
Liu, X., Chen, Y., Wang, L., Peng, D.L.: Transition from paramagnetism to ferromagnetism in HfO2 nanorods. J. Appl. Phys. 113, 076102 (2013)ADSCrossRefGoogle Scholar
Ran, J., Yan, Z.: Observation of ferromagnetism in highly oxygen-deficient HfO2 films. J. Semicond. 30, 102002 (2009)ADSCrossRefGoogle Scholar
Pemmaraju, C.D., Sanvito, S.: Ferromagnetism driven by intrinsic point defects in HfO2. Phys. Rev. Lett. 94, 217205 (2005)ADSCrossRefGoogle Scholar
Weng, H., Dong, J.: Ferromagnetism in HfO2 induced by hole doping: first-principles calculations. Phys. Rev. B 73, 132410 (2006)ADSCrossRefGoogle Scholar
Beltrán, J., Muñoz, M., Hafner, J.: Structural, electronic and magnetic properties of the surfaces of tetragonal and cubic HfO2. New J. Phys. 10, 063031 (2008)ADSCrossRefGoogle Scholar
Wang, M., Feng, M., Lu, Y.: Possible origin of ferromagnetism in undoped monoclinic HfO2 film. Comput. Mater. Sci. 92, 120–126 (2014)CrossRefGoogle Scholar