Donor impurity band exchange in dilute ferromagnetic oxides
Source abstract
Abstract
Dilute ferromagnetic oxides having Curie temperatures far in excess of 300 K and exceptionally large ordered moments per transition-metal cation challenge our understanding of magnetism in solids. These materials are high-k dielectrics with degenerate or thermally activated n-type semiconductivity. Conventional super-exchange or double-exchange interactions cannot produce long-range magnetic order at concentrations of magnetic cations of a few percent. We propose that ferromagnetic exchange here, and in dilute ferromagnetic nitrides, is mediated by shallow donor electrons that form bound magnetic polarons, which overlap to create a spin-split impurity band. The Curie temperature in the mean-field approximation varies as (xdelta)(1/2) where x and delta are the concentrations of magnetic cations and donors, respectively. High Curie temperatures arise only when empty minority-spin or majority-spin d states lie at the Fermi level in the impurity band. The magnetic phase diagram includes regions of semiconducting and metallic ferromagnetism, cluster paramagnetism, spin glass and canted antiferromagnetism.
Source: europepmc · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: ZnO doping and properties · Semiconductor materials and devices · Electronic and Structural Properties of Oxides
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (44)
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1. Prellier, W., Fouchet, A. & Mercey, B. Oxide-diluted magnetic semiconductors: a review of the experimental status. J. Phys. Condens. Matter 15, R1583–R1601 (2003).10.1088/0953-8984/15/37/R01 ↗
2. Pearton, S. J. et al. Wide band gap ferromagnetic semiconductors and oxides J. Appl. Phys. 93, 1–13 (2003).10.1063/1.1517164 ↗
3. Dietl, T. et al. Zener model description of ferromagnetism in zinc-blende magnetic semiconductors. Science 287, 1019–1022 (2000).10.1126/science.287.5455.1019 ↗
4. Matsumoto, Y. et al. Room-temperature ferromagnetism in transparent transition metal-doped titanium dioxide Science 291, 854–856 (2001).10.1126/science.1056186 ↗
5. Ueda, K., Tabata, H. & Kawai, T. Magnetic and electric properties of transition-metal-doped ZnO films. Appl. Phys. Lett. 79, 988–990 (2001).10.1063/1.1384478 ↗
6. Ogale, S. B. et al. High temperature ferromagnetism with a giant magnetic moment in transparent Co-doped SnO2-δ . Phys. Rev. Lett. 91, 077205 (2003).10.1103/PhysRevLett.91.077205 ↗
7. Kim, J. Y. et al. Ferromagnetism induced by clustered Co in Co-doped anatase TiO2 thin films Phys. Rev. Lett. 90, 017401 (2003).10.1103/PhysRevLett.90.017401 ↗
8. Punnoose, A., Seehra, M. S., Park, W. K. & Moodera, J. S. On the room temperature ferromagnetism in Co-doped TiO2 films. J. Appl. Phys. 93, 7867–7869 (2003).10.1063/1.1556121 ↗
9. Rode, K. et al. Magnetic semiconductors based on cobalt substituted ZnO. J. Appl. Phys. 93, 7676–7678 (2003).10.1063/1.1556115 ↗
10. Ramachandran, S., Tiwari, A. & Narayan, J. Zn0.9Co0.1O-based diluted magnetic semiconducting thin films. Appl. Phys. Lett. 84, 5255–5257 (2004).10.1063/1.1764936 ↗
11. Goodenough, J. B. Magnetism and the Chemical Bond (Interscience, New York, 1963).
12. Holtzberg, F., von Molnar, S. & Coey, J. M. D. Handbook on Semiconductors Vol. 3 (ed. Keller, S.) 850 (North Holland, Amsterdam, 1980).
13. Dietl, T. Ferromagnetic semiconductors. Semicond. Sci. Technol. 17, 377–392 (2002).10.1088/0268-1242/17/4/310 ↗
14. Mott, N. F. Conduction in Noncrystalline Materials (Oxford Univ. Press, Oxford, 1987).
15. von Molnar, S. & Kasuya, T. in Proceedings of 10th International Conference on Physics of Semiconductors (eds Keller, S. P., Hensel, J. C. & Stern, F.) 233 (U.S.A.E.C. Division of Technical Information, Springfield, Vancouver, 1970).
16. Dietl, T. & Spalek, J. J. Effect of thermodynamic fluctuations of magnetization on the bound magnetic polaron in dilute magnetic semiconductors. Phys. Rev. B 28, 1548–1563 (1983).10.1103/PhysRevB.28.1548 ↗
17. Wolff, P. A. Semiconductors and Semimetals Vol. 25 (eds Furdyna, J. R. & Kossut, J.) (Academic, San Diego 1988).
18. Angelescu, D. E. & Bhatt, R. N. Effective interaction Hamiltonian of polaron pairs in diluted magnetic semiconductors. Phys. Rev. B 65, 075211 (2002).10.1103/PhysRevB.65.075211 ↗
19. Durst, A. C., Bhatt, R. N. & Wolff, P. A. Bound magnetic polaron interactions in insulating doped diluted magnetic semiconductors. Phys. Rev. B 65, 235205 (2002).10.1103/PhysRevB.65.235205 ↗
20. Zallen, R. M. Physics of Amorphous Solids (Wiley, New York, 1983).10.1002/3527602798 ↗
21. Kaminski, A. & Das Sarma, S. Polaron percolation in diluted magnetic semiconductors. Phys. Rev. Lett. 88, 247202 (2002).10.1103/PhysRevLett.88.247202 ↗
22. Kasuya, T. Mobility of antiferromagnetic large polaron. Solid State Commun. 8, 1635 (1970).10.1016/0038-1098(70)90480-1 ↗
23. Kim, K. J. & Park, Y. R. Spectroscopic ellipsometry study of optical transitions in Zn1-xCoxO alloys. Appl. Phys. Lett. 81, 1420–1422 (2002).10.1063/1.1501765 ↗
24. Berciu, M. & Bhatt, R. N. Effects of disorder on ferromagnetism in diluted magnetic semiconductors. Phys. Rev. Lett. 87, 107203 (2001).10.1103/PhysRevLett.87.107203 ↗
25. Das Sarma, S., Hwang, E. W. & Kaminski, A. Temperature-dependent magnetization in diluted magnetic semiconductors. Phys. Rev. B 67, 155201 (2003).10.1103/PhysRevB.67.155201 ↗
26. Wilson, J. A. Systematics of breakdown of Mott insulation in binary transition-metal compounds. Adv. Phys. 21, 143 (1972).10.1080/00018737200101278 ↗
27. Saeki, H., Tabata, H. & Kawai, T. Magnetic and electric properties of vanadium doped ZnO films. Solid State Commun. 120, 439–443 (2001).10.1016/S0038-1098(01)00400-8 ↗
28. Hong, N.Y H., Sakai, J. & Hassini, A. Ferromagnetism at room temperature with a large magnetic moment in anatase V- doped TiO2 thin films. Appl. Phys. Lett. 84, 2602–2604 (2004).10.1063/1.1703848 ↗
29. Venkatesan, M., Fitzgerald, C. B. & Coey, J. M. D. Unexpected magnetism in a dielectric oxide. Nature 430, 630–630 (2004).10.1038/430630a ↗
30. Mattis, D. C. Theory of Magnetism Vol. 1 (Springer, Berlin, 1981).10.1007/978-3-642-83238-3 ↗
31. Yahia, J. Dependence of electrical conductivity and thermoelectric power of pure and aluminium-doped rutile on equilibrium oxygen pressure and temperature. Phys. Rev. 130, 1711–1719 (1963).10.1103/PhysRev.130.1711 ↗
32. Kohan, A. F., Ceder, G., Morgan, D. & Van de Walle, C. G. First-principles study of native point defects in ZnO. Phys. Rev. B 61, 15019–15027 (2000).10.1103/PhysRevB.61.15019 ↗
33. Stoneham, A. M. Theory of Defects in Solids Ch. 16 (Clarendon, Oxford 1975).
34. Sonoda, S., Shimizu, S., Sasaki, T., Yamamoto, Y. & Hori, H. Moleclar beam epitaxy of wurtzite (Ga,Mn)N films on sapphire (0001) showing the ferromagnetic behaviour at room temperature. J. Cryst. Growth 237, 1358–1362 (2002).10.1016/S0022-0248(01)02183-2 ↗
35. Hashimoto, M., Zhou, Y. K., Kanamura, M. & Asahi, H. High-temperature (>400K) ferromagnetism in III-V based diluted magnetic semiconductor GaCrN grown by ECR molecular-beam epitaxy. Solid State Commun. 122, 37–39 (2002).10.1016/S0038-1098(02)00073-X ↗
36. Wu, S. Y. et al. Synthesis, Characterization and modeling of high-quality ferromagnetic Cr-doped AlN thin films. Appl. Phys. Lett. 82, 3047–3049 (2003).10.1063/1.1570521 ↗
37. Shinde, S. R. et al. Ferromagnetism in laser-deposited anatase Ti1-xCoxO2-δ films. Phys. Rev B 67, 115211 (2003).10.1103/PhysRevB.67.115211 ↗
38. Wang, Z. J., Tang, J. K., Tung, L. D., Zhou, W. L. & Spinu, L. Ferromagnetism and transport properties of Fe-doped reduced-rutile TiO2-δ films. J. Appl. Phys. 93, 7870–7872 (2003).10.1063/1.1556122 ↗
39. Coey, J. M. D., Douvalis, A. P., Fitzgerald, C. B. & Venkatesan, M. Ferromagnetism in Fe-doped SnO2 films. Appl. Phys. Lett. 84, 1332–1334 (2004).10.1063/1.1650041 ↗
40. Sharma, P. et al. Ferromagnetism above room temperature in bulk and transparent thin films of Mn-doped ZnO. Nature Mater. 2, 673–677 (2003).10.1038/nmat984 ↗
41. Han, S. J. et al. Magnetism in Mn-doped ZnO bulk samples prepared by solid-state reaction. Appl. Phys. Lett. 83, 920–922 (2003).10.1063/1.1597414 ↗
42. Radovanovic, P. V. & Gamelin, D. R. High-temperature ferromagnetism in Ni2+-doped ZnO aggregates prepared from colloidal diluted magnetic semiconductor quantum dots. Phys. Rev. Lett. 91, 157202 (2003).10.1103/PhysRevLett.91.157202 ↗
43. Kale, S. N. et al. Magnetism in cobalt-doped Cu2O thin films without and without Al, V and Zn codopants. Appl. Phys. Lett. 83, 2100–2102 (2003).10.1063/1.1564864 ↗
44. Philip, J., Theodoropolou, N., Berera, G., Moodera, J. S. & Satpati, B. High-temperature ferromagnetism in manganese-doped indium-tin oxide films. Appl. Phys. Lett. 85, 777–779 (2004).10.1063/1.1773617 ↗