Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-28T07:35:54.572Z Has data issue: false hasContentIssue false

Defect-mediated ferromagnetism and controlled switching characteristics in ZnO

Published online by Cambridge University Press:  11 May 2011

Siddhartha Mal*
Affiliation:
Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695
Sudhakar Nori
Affiliation:
Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695
Jagdish Narayan
Affiliation:
Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695
John T. Prater
Affiliation:
Materials Science Division, Army Research Office, Research Triangle Park, North Carolina 27709
*
a)Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

We report a detailed study of the structural, chemical, electrical, and magnetic properties of undoped ZnO thin films grown under different conditions and the films that were annealed in various environments and irradiated with an ultraviolet laser. Samples prepared in low oxygen pressure or subsequently annealed in vacuum have always been strongly magnetic. Oxygen-annealed films displayed a sequential transition from the ferromagnetic to the diamagnetic state as a function of the annealing temperature. Reversible switching of room temperature ferromagnetism and n-type conductivity have been demonstrated either by annealing in different environments or by a novel laser irradiation treatment. Enhancements in both the electrical conductivity and magnetic moment have been controlled precisely with laser pulses, without altering the crystal structure. Electron paramagnetic resonance data were found to be in good agreement with the magnetization and conductivity measurements. Our secondary ion mass spectrometer and electron energy loss spectrometer studies conclusively rule out the presence of any external ferromagnetic impurities.

Type
Articles
Copyright
Copyright © Materials Research Society 2011

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1.Ohno, H.: Making nonmagnetic semiconductor ferromagnetic. Science 281, 951 (1998).Google Scholar
2.Dietl, T.: Dilute magnetic semiconductors: Functional ferromagnets. Nat. Mater. 2, 646 (2003).Google Scholar
3.Ramachandran, S., Tiwari, A., and Narayan, J.: Zn0.9Co0.1O-based diluted magnetic semiconducting thin films. Appl. Phys. Lett. 84, 5255 (2004).Google Scholar
4.Ueda, K., Tabata, H., and Kawai, T.: Magnetic and electric properties of transition-metal-doped ZnO films. Appl. Phys. Lett. 79, 988 (2001).Google Scholar
5.Rao, C.N.R. and Deepak, F.L.: Absence of ferromagnetism in Mn and Co doped ZnO. J. Mater. Chem. 15, 573 (2005).Google Scholar
6.Kaspar, T.C., Droubay, T., Heald, S.M., Nachimuthu, P., Wang, C.M., Shutthanandan, V., Johnson, C.A., Gamelin, D.R., and Chambers, S.A.: Lack of ferromagnetism in n-type cobalt-doped ZnO epitaxial thin films. New J. Phys. 10, 055010 (2008).Google Scholar
7.Gacic, M., Jakob, G., Herbort, C., Adrian, H., Tietze, T., Brück, S., and Goering, E.: Magnetism of Co-doped ZnO thin films. Phys. Rev. B 75, 205206 (2007).Google Scholar
8.Venkatesan, M., Fitzgerald, C.B., and Coey, J.M.D.: Thin films: Unexpected magnetism in a dielectric oxide. Nature 430, 630 (2004).CrossRefGoogle Scholar
9.Hong, N.H., Sakai, J., Poirot, N., and Brize, V.: Room-temperature ferromagnetism observed in undoped semiconducting and insulating oxide thin films. Phys. Rev. B 73, 132404 (2006).Google Scholar
10.Coey, J.M.D.: d 0 ferromagnetism. Solid State Sci. 7, 660 (2005).Google Scholar
11.Kim, D., Hong, J., Park, Y.R., and Kim, K.J.: The origin of oxygen vacancy induced ferromagnetism in undoped TiO2. J. Phys. Condens. Matter 21, 195405 (2009).CrossRefGoogle Scholar
12.Sudaresan, A., Bhargavi, R., Rangarajan, N., Siddesh, U., and Rao, C.N.R.: Ferromagnetism as a universal feature of nanoparticles of the otherwise nonmagnetic oxides. Phys. Rev. B 74, 161306(R) (2006).Google Scholar
13.Panigrahy, B., Aslam, M., Misra, D.S., Ghosh, M., and Bahadur, D.: Defect-related emissions and magnetization properties of ZnO nanorods. Adv. Funct. Mater. 20, 1161 (2010).Google Scholar
14.Xing, G., Wang, D., Yi, J., Yang, L., Gao, M., He, M., Yang, J., Ding, J., Sum, T.C., and Wu, T.: Correlated d 0 ferromagnetism and photoluminescence in undoped ZnO nanowires. Appl. Phys. Lett. 96, 112511 (2010).Google Scholar
15.Kapilashrami, M., Xu, J., Strom, V., Rao, K.V., and Belova, L.: Transition from ferromagnetism to diamagnetism in undoped ZnO thin films. Appl. Phys. Lett. 95, 033104 (2009).Google Scholar
16.Narayan, J., Nori, S., Pandya, D.K., Avasthi, D.K., and Smirnov, A.I.: Defect dependent ferromagnetism in MgO doped with Ni and Co. Appl. Phys. Lett. 93, 082507 (2008).Google Scholar
17.Wang, Q., Sun, Q., Chen, G., Kawazoe, Y., and Jena, P.: Vacancy-induced magnetism in ZnO thin films and nanowires. Phys. Rev. B 77, 205411 (2008).CrossRefGoogle Scholar
18.Potzger, K., Zhou, S., Grenzer, J., Helm, M., and Fassbender, J.: An easy mechanical way to create ferromagnetic defective ZnO. Appl. Phys. Lett. 92, 182504 (2008).Google Scholar
19.Smirnov, A.I. and Smirnova, T.I.: High-field ESR spectroscopy in membrane and protein biophysics, in Biological Magnetic Resonance, edited by Berliner, L.J. and Bender, C. (Kluwer, New York, 2004); Vol. 21, pp. 277348.Google Scholar
20.Sudhakar, C., Kharel, P., Lawes, G., Suryanarayanan, R., Naik, R., and Naik, V.M.: Raman spectroscopic studies of oxygen defects in Co-doped ZnO films exhibiting room-temperature ferromagnetism. J. Phys. Condens. Matter 19, 026212 (2007).Google Scholar
21.Roro, K.T., Kassier, G.H., Dangbegnon, J.K., Sivaraya, S., Westraadt, J.E., Neethling, J.H., Leitch, A.W.R., and Botha, J.R.: Temperature-dependent Hall effect studies of ZnO thin films grown by metalorganic chemical vapour deposition. Semicond. Sci. Technol. 23, 055021 (2008).Google Scholar
22.Chakraborti, D., Trichy, G., Narayan, J., Prater, J.T., and Kumar, D.: Effect of Al doping on the magnetic and electrical properties of Zn(Cu)O based diluted magnetic semiconductors. J. Appl. Phys. 102, 113908 (2007).Google Scholar
23.Ye, L.H., Freeman, A.J., and Delley, B.: Half-metallic ferromagnetism in Cu-doped ZnO: Density-functional calculations. Phys. Rev. B 73, 033203 (2006).Google Scholar
24.Cebulla, R., Weridt, R., and Ellmer, K.: Al-doped zinc oxide films deposited by simultaneous rf and dc excitation of a magnetron plasma: Relationships between plasma parameters and structural and electrical film properties. J. Appl. Phys. 83, 1087 (1998).Google Scholar
25.Rao, L.K. and Vinni, V.: Novel mechanism for high speed growth of transparent and conducting tin oxide thin films by spray pyrolysis. Appl. Phys. Lett. 63, 608 (1999).Google Scholar
26.Fan, J.C.C. and Goodenough, J.B.: X-ray photoemission spectroscopy studies of Sn‐doped indium‐oxide films. J. Appl. Phys. 48, 3524 (1977).Google Scholar
27.Coey, J.M.D.: Dilute magnetic oxides. Curr. Opin. Solid State Mater. Sci. 10, 83 (2006).Google Scholar
28.Janotti, A. and Van de Walle, C.G.: Fundamentals of zinc oxide as a semiconductor. Rep. Prog. Phys. 72, 126501 (2009).Google Scholar
29.Kim, Y.-S. and Park, C.H.: Rich variety of defects in ZnO via an attractive interaction between O vacancies and Zn interstitials: Origin of n-type doping. Phys. Rev. Lett. 102, 086403 (2009).Google Scholar
30.Jug, K. and Tikhomirov, V.A.: Influence of intrinsic defects on the properties of zinc oxide. J. Comput. Chem. 29, 2250 (2008).Google Scholar
31.Lany, S. and Zunger, A.: Anion vacancies as a source of persistent photoconductivity in II-VI and chalcopyrite semiconductors. Phys. Rev. B 72, 035215 (2005).Google Scholar
32.Janotti, A. and Van de Walle, C.G.: Native point defects in ZnO. Phys. Rev. B 76, 165202 (2007).Google Scholar
33.Abragam, A. and Bleaney, B.: Electron Paramagnetic Resonance of Transition ions (Dover publications Inc., New York, 1986).Google Scholar
34.Jain, V.K. and Lehmann, G.: Electron paramagnetic resonance of Mn2+ in orthorhombic and higher symmetry crystals. Phys. Status Solidi B Basic Res. 159, 495 (1990).Google Scholar
35.Dyson, F.J.: Electron spin resonance absorption in metals. II. Theory of electron diffusion and the skin effect. Phys. Rev. 98, 349 (1955).Google Scholar
36.Son, N.T., Ivanov, I.G., Kuznetsov, A., Svensson, B.G., Zhao, Q.X., Willander, M., Morishita, N., Ohshima, T., Itoh, H., Isoya, J., Janzén, E., and Yakimova, R.: Recombination centers in as-grown and electron-irradiated ZnO substrates. J. Appl. Phys. 102, 093504 (2007).Google Scholar
37.Wang, X.J., Vlasenko, L.S., Pearton, S.J., Chen, W.M., and Buyanova, I.A.: Oxygen and zinc vacancies in as-grown ZnO single crystals. J. Phys. D Appl. Phys. 42, 175411 (2009).Google Scholar
38.Galland, D. and Herve, A.: ESR spectra of the zinc vacancy in ZnO. Phys. Lett. 33A, 1 (1970).Google Scholar
39.Locker, D.R. and Meese, J.M.: Displacement thresholds in ZnO. IEEE Trans. Nucl. Sci. 19, 237 (1972).Google Scholar
40.Gonzalez, C., Galland, D., and Herv, A.: Hyperfine interactions of the F+ center in ZnO. Phys. Status Solidi B 72, 309 (1975).Google Scholar
41.Vlasenko, L.S. and Watkins, G.D.: Optical detection of electron paramagnetic resonance for intrinsic defects produced in ZnO by 2.5-MeV electron irradiation in situ at 4.2 K. Phys. Rev. B 72, 035203 (2005).CrossRefGoogle Scholar
42.Kappers, L.A., Gilliam, O.R., Evans, S.M., Halliburton, L.E., and Giles, N.C.: EPR and optical study of oxygen and zinc vacancies in electron-irradiated ZnO. Nucl. Instrum. Methods Phys. Res., B 266, 2953 (2008).Google Scholar
43.Taylor, A.L., Filipovich, G., and Lindeberg, G.K.: Identification of Cd vacancies in neutron-irradiated CdS by electron paramagnetic resonance. Solid State Commun. 8, 1359 (1970).Google Scholar