1887
banner image
No data available.
Please log in to see this content.
You have no subscription access to this content.
No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
oa
Defect-induced magnetism in undoped wide band gap oxides: Zinc vacancies in ZnO as an example
Rent:
Rent this article for
Access full text Article
/content/aip/journal/adva/1/2/10.1063/1.3609964
1.
1. T. Dietl, H. Ohno, F. Matsukura, J. Cibert, and D. Ferrand, Science 287, 1019 (2000).
http://dx.doi.org/10.1126/science.287.5455.1019
2.
2. I. Žutić, J. Fabian, and S. Das Sarma, Rev. Mod. Phys. 76, 323 (2004).
http://dx.doi.org/10.1103/RevModPhys.76.323
3.
3. S. J. Pearton, C. R. Abernathy, M. E. Overberg, G. T. Thaler, D. P. Norton, Y. D. Park, F. Ren, J. Kim, and L. A. Boatner, J. Appl. Phys. 93, 1 (2003).
http://dx.doi.org/10.1063/1.1517164
4.
4. T. Dietl, D. D. Awschalom, M. Kaminska, and H. Ohno, Spintronics (Elsevier Press, UK, 2008).
5.
5. J. B. Yi, C. C. Lim, G. Z. Xing, H. M. Fan, L. H. Van, S. L. Huang, K. S. Yang, X. L. Huang, X. B. Qin, B. Y. Wang, T. Wu, L. Wang, H. T. Zhang, X. Y. Gao, T. Liu, A. T. S. Wee, Y. P. Feng, and J. Ding, Phys. Rev. Lett. 104, 137201 (2010).
http://dx.doi.org/10.1103/PhysRevLett.104.137201
6.
6. J. M. D. Coey, P. Stamenov, R. D. Gunning, M. Venkatesan and K. Paul, New J. Phys. 12, 053025 (2010).
http://dx.doi.org/10.1088/1367-2630/12/5/053025
7.
7. S. B. Ogale, Adv. Mater. 22, 3125 (2010).
http://dx.doi.org/10.1002/adma.200903891
8.
8. Ü. Özgür, Y. I. Alivov, C. Liu, A. Teke, M. A. Reshchikov, S. Doğan, V. Avrutin, S. J. Cho, and H. Morko, J. Appl. Phys. 98, 041301 (2005).
http://dx.doi.org/10.1063/1.1992666
9.
9. C. Jagadish and S. J. Pearton, Zinc Oxide Bulk, Thin Films and nanostructures (Elsevier Press, UK, 2006).
10.
10. C. Klingshirn, Chemphyschem 8, 782 (2007).
http://dx.doi.org/10.1002/cphc.200700002
11.
11. G. Z. Xing, X. S. Fang, Z. Zhang, D. D. Wang, X. Huang, J. Guo, L. Liao, Z. Zheng, H. R. Xu, T. Yu, Z. X. Shen, C. H. A. Huan, T. C. Sum, H. Zhang, and T. Wu, Nanotechnology 21, 255701 (2010).
http://dx.doi.org/10.1088/0957-4484/21/25/255701
12.
12. K. Ando, H. Saito, Z. Jin, T. Fukumura, M. Kawasaki, Y. Matsumoto, and H. Koinuma, J. Appl. Phys. 89, 7284 (2001).
http://dx.doi.org/10.1063/1.1356035
13.
13. K. R. Kittilstved, N. S. Norberg, and D. R. Gamelin, Phys. Rev. Lett. 94, 147209 (2005).
http://dx.doi.org/10.1103/PhysRevLett.94.147209
14.
14. G. Z. Xing, J. B. Yi, J. G. Tao, T. Liu, L. M. Wong, Z. Zhang, G. P. Li, S. J. Wang, J. Ding, T. C. Sum, C. H. A. Huan, and T. Wu, Adv. Mater. 20, 3521 (2008).
http://dx.doi.org/10.1002/adma.200703149
15.
15. M. Snure, D. Kumar, and A. Tiwari, JOM 61, 72 (2009).
http://dx.doi.org/10.1007/s11837-009-0092-9
16.
16. D. W. Abraham, M. M. Frank, and S. Guha, Appl. Phys. Lett. 87, 252502 (2005).
http://dx.doi.org/10.1063/1.2146057
17.
17. M. D. McCluskey and S. J. Jokela, J. Appl. Phys. 106, 071101 (2009).
http://dx.doi.org/10.1063/1.3216464
18.
18. S. R. Shinde, S. B. Ogale, J. S. Higgins, H. Zheng, A. J. Millis, V. N. Kulkarni, R. Ramesh, R. L. Greene, and T. Venkatesan, Phys. Rev. Lett. 92, 166601 (2004).
http://dx.doi.org/10.1103/PhysRevLett.92.166601
19.
19. J.-Y. Kim, J.-H. Park, B.-G. Park, H.-J. Noh, S.-J. Oh, J. S. Yang, D.-H. Kim, S. D. Bu, T.-W. Noh, H.-J. Lin, H.-H. Hsieh, and C. T. Chen, Phys. Rev. Lett. 90, 017401 (2003).
http://dx.doi.org/10.1103/PhysRevLett.90.017401
20.
20. J. M. D. Coey, Solid State Sci. 7, 660 (2005).
http://dx.doi.org/10.1016/j.solidstatesciences.2004.11.012
21.
21. J. M. D. Coey, M. Venkatesan and C. B. Fitzgerald, Nat. Mater., 4, 173 (2005).
http://dx.doi.org/10.1038/nmat1310
22.
22. H. W. Peng, H. J. Xiang, S- H. Wei, S.- S. Li, J.- B. Xia, and J. B. Li, Phys. Rev. Lett. 102, 017201 (2009).
http://dx.doi.org/10.1103/PhysRevLett.102.017201
23.
23. Q. Y. Xu, H. Schmidt, S. Zhou, K. Potzger, M. Helm, H. Hochmuth, M. Lorenz, A. Setzer, P. Esquinazi, C. Meinecke, and M. Grundmann, Appl. Phys. Lett. 92, 082508 (2008).
http://dx.doi.org/10.1063/1.2885730
24.
24. S. Banerjee, M. Mandal, N. Gayathri, and M. Sardar, Appl. Phys. Lett. 91, 182501 (2007).
http://dx.doi.org/10.1063/1.2804081
25.
25. K. Potzger, Z. Shengqiang, J. Grenzer, M. Helm, and J. Fassbender, Appl. Phys. Lett. 92, 182504 (2008).
http://dx.doi.org/10.1063/1.2921782
26.
26. M. Khalid, M. Ziese, A. Setzer, P. Esquinazi, M. Lorenz, H. Hochmuth, M. Grundmann, D. Spemann, T. Butz, G. Brauer, W. Anwand, G. Fischer, W. A. Adeagbo, W. Hergert, and A. Ernst, Phys. Rev. B 80, 035331 (2009).
http://dx.doi.org/10.1103/PhysRevB.80.035331
27.
27. Q. Wang, Q. Sun, G. Chen, Y. Kawazoe, and P. Jena, Phys. Rev. B 77, 205411 (2008).
http://dx.doi.org/10.1103/PhysRevB.77.205411
28.
28. D. Q. Gao, Z. H. Zhang, J. L. Fu, Y. Xu, J. Qi, and D. S. Xue, J. Appl. Phys. 105, 113928 (2009).
http://dx.doi.org/10.1063/1.3143103
29.
29. S. Majumder, D. Paramanik, A. Gupta and Shikha Varma, Appl. Surf. Sci. 256, 513 (2009).
http://dx.doi.org/10.1016/j.apsusc.2009.07.096
30.
30. N. H. Hong, A. Barla, J. Sakai, N. Q. Huong, Phys. Stat. Sol. C 4, 4461 (2007).
http://dx.doi.org/10.1002/pssc.200777342
31.
31. Y. F. Li, R. Deng, B. Yao, G. Z. Xing, D. D. Wang, and Tom Wu, Appl. Phys. Lett. 97, 102506 (2010).
http://dx.doi.org/10.1063/1.3485058
32.
32. X. Zhang, Y. H. Cheng, L. Y. Li, Hui Liu, X. Zuo, G. H. Wen, L. Li, R. K. Zheng, and S. P. Ringer, Phys. Rev. B 80, 174427 (2009).
http://dx.doi.org/10.1103/PhysRevB.80.174427
33.
33. A. L. Schoenhalz, J. T. Arantes, A. Fazzio, and G. M. Dalpian, Appl. Phys. Lett. 94, 162503 (2009).
http://dx.doi.org/10.1063/1.3119640
34.
34. D. Kim, J. H. Yang, and J. Hong, J. Appl. Phys. 106, 013908 (2009).
http://dx.doi.org/10.1063/1.3158535
35.
35. M. Venkatesan, C. Fitzgerald, and J. M. D. Coey, Nature (London) 430, 630 (2004).
http://dx.doi.org/10.1038/430630a
36.
36. N. H. Hong, J. Sakai, N. Poirot, and V. Brize, Phys. Rev. B 73, 132404 (2006).
http://dx.doi.org/10.1103/PhysRevB.73.132404
37.
37. N. H. Hong, N. Poirot, and J. Sakai, Phys. Rev. B 77, 033205 (2008).
http://dx.doi.org/10.1103/PhysRevB.77.033205
38.
38. G. Z. Xing, J. B. Yi, D. D. Wang, L. Liao, T. Yu, Z. X. Shen, C. H. A. Huan, T. C. Sum, J. Ding, and T. Wu, Phys. Rev. B 79, 174406 (2009).
http://dx.doi.org/10.1103/PhysRevB.79.174406
39.
39. J. A. Chan, S. Lany, and A. Zunger, Phys. Rev. Lett. 103, 016404 (2009).
http://dx.doi.org/10.1103/PhysRevLett.103.016404
40.
40. C. M. Araujo, M. Kapilashrami, J. Xu, O. D. Jayakumar, S. Nagar, Y. Wu, C. Århammar, B. Johansson, L. Belova, R. Ahuja, G. A. Gehring, and K. V. Rao, Appl. Phys. Lett. 96, 232505 (2010).
http://dx.doi.org/10.1063/1.3447376
41.
41. L. Liao, B. Yan, Y. F. Hao, G. Z. Xing, J. P. Liu, B. C. Zhao, Z. X. Shen, T. Wu, L. Wang, J. T. L. Thong, C. M. Li, W. Huang, and T. Yu, Appl. Phys. Lett. 94, 113106 (2009).
http://dx.doi.org/10.1063/1.3097029
42.
42. S. D. Yoon, Y. Chen, A. Yang, T. L. Goodrich, X. Zuo, D. A. Arena, K. Ziemer, C. Vittoria, and V. G. Harris, J. Phys.: Condens. Matter 18, L355 (2006).
http://dx.doi.org/10.1088/0953-8984/18/27/L01
43.
43. A. Sundaresan, R. Bhargavi, N. Rangarajan, U. Siddesh, and C. N. R. Rao, Phys. Rev. B. 74, 161306R (2006).
http://dx.doi.org/10.1103/PhysRevB.74.161306
44.
44. Q. Y. Xu, S. Q. Zhou and H. Schmidt, J. Alloys Compd. 487, 665 (2009).
http://dx.doi.org/10.1016/j.jallcom.2009.08.033
45.
45. J. P. Xu, S. B. Shi, L. Li, X. S. Zhang, Y. X. Wang and X. M. Chen, Chin. Phys. Lett. 27, 047803 (2010).
http://dx.doi.org/10.1088/0256-307X/27/4/047803
46.
46. L. H. Xu, X. Y. Li and J. Yuan, Superlatt. Microstruc. 44, 276 (2008).
http://dx.doi.org/10.1016/j.spmi.2008.04.004
47.
47. Z. P. Wei, Y. M. Lu, D. Z. Shen, Z. Z. Zhang, B. Yao, B. H. Li, J. Y. Zhang, D. X. Zhao, X. W. Fan, and Z. K. Tang, Appl. Phys. Lett. 90, 042113 (2007).
http://dx.doi.org/10.1063/1.2435699
48.
48.JCPDS Card. No. 36-1451.
49.
49. L. Znaidi, J. Sol-Gel Sci. Technol 26, 817 (2003).
50.
50. J. Philip, A. Punnoose, B. I. Kim, K. M. Reddy, S. Layne, J. O. Holmes, B. Satpati, P. R. Leclair, T. S. Santos, and J. S. Moodera, Nat. Mater. 5, 298 (2006).
http://dx.doi.org/10.1038/nmat1613
51.
51. S. B. Ogale, R. J. Choudhary, J. P. Buban, S. E. Lofland, S. R. Shinde, S. N. Kale, V. N. Kulkarni, J. Higgins, C. Lanci, J. R. Simpson, N. D. Browning, S. Das Sarma, H. D. Drew, R. L. Greene, and T. Venkatesan, Phys. Rev. Lett. 91, 077205 (2003).
http://dx.doi.org/10.1103/PhysRevLett.91.077205
52.
52. N. F. Mott, J. Non-Cryst. Solids 1, 1 (1968).
http://dx.doi.org/10.1016/0022-3093(68)90002-1
53.
53. Y. Natsume, H. Sakata, and T. Hirayama, Phys. Status Solidi A 148, 485 (1995).
http://dx.doi.org/10.1002/pssa.2211480217
54.
54. S. Bandyopadhyay, G. K. Paul, R. Roy, S. K. Sen, and S. Sen, Mater. Chem. Phys. 74, 83 (2002).
http://dx.doi.org/10.1016/S0254-0584(01)00402-3
55.
55. S. Singh and M. S. Ramachandra Rao, Phys. Rev. B 80, 045210 (2009).
http://dx.doi.org/10.1103/PhysRevB.80.045210
56.
56. F. Reuss, S. Frank, C. Kirchner, R. Kling, Th. Gruber, and A. Waag, Appl. Phys. Lett. 87, 112104 (2005).
http://dx.doi.org/10.1063/1.2045553
57.
57. B. Raquet, M. Goiran, N. Nègre, J. Léotin, B. Aronzon, V. Rylkov, and E. Meilikhov, Phys. Rev. B 62, 17144 (2000).
http://dx.doi.org/10.1103/PhysRevB.62.17144
58.
58. N. Nagaosa, J. Sinova, S. Onoda, A. H. MacDonald and N. P. Ong, Rev. Mod. Phys. 82, 1539 (2010).
http://dx.doi.org/10.1103/RevModPhys.82.1539
59.
59. A. J. Behan, A. Mokhtari, H. J. Blythe, D. Score, X-H. Xu, J. R. Neal, A. M. Fox, and G. A. Gehring, Phys. Rev. Lett. 100, 047206 (2008).
http://dx.doi.org/10.1103/PhysRevLett.100.047206
60.
60. H. S. Hsu, C. P. Lin, H. Chou and J. C. A. Huang, Appl. Phys. Lett. 93, 142507 (2008).
http://dx.doi.org/10.1063/1.3000015
61.
61. A. Janotti and C. G. Van de Walle, Rep. Prog. Phys. 72, 126501 (2009).
http://dx.doi.org/10.1088/0034-4885/72/12/126501
62.
62. A. B. Djurišić and Y. H. Leung, Small 2, 944 (2006).
http://dx.doi.org/10.1002/smll.200600134
63.
63. X. J. Wang, L. S. Vlasenko, S. J. Pearton, W. M. Chen and I. A. Buyanova, J. Phys. D: Appl. Phys. 42, 175411 (2009).
http://dx.doi.org/10.1088/0022-3727/42/17/175411
64.
64. B. J. Pierce and R. L. Hengehold, J. Appl. Phys. 47, 644 (1976).
http://dx.doi.org/10.1063/1.322627
65.
65. D. C. Reynolds, D. C. Look, B. Jogai, C. W. Litton, T. C. Collins, W. Harsch, and G. Cantwell, Phys. Rev. B 57, 12151 (1998).
http://dx.doi.org/10.1103/PhysRevB.57.12151
66.
66. J. R. Haynes, Phys. Rev. Lett. 4, 361 (1960).
http://dx.doi.org/10.1103/PhysRevLett.4.361
67.
67. S. B. Zhang, S.-H. Wei, and Alex Zunger, Phys. Rev. B 63, 075205 (2001).
http://dx.doi.org/10.1103/PhysRevB.63.075205
68.
68. P. Erhart and K. Albe, Phys. Rev. B 73, 115207 (2006).
http://dx.doi.org/10.1103/PhysRevB.73.115207
69.
69. Y. Q. Gai, B. Yao, Y. F. Li, Y. M. Lu, D. Z. Shen, J. Y. Zhang, D. X. Zhao, X. W. Fan and T. Cui, Phys. Lett. A 372, 5077 (2008).
http://dx.doi.org/10.1016/j.physleta.2008.05.055
70.
70. Y. W. Heo, D. P. Norton and S. J. Pearton, J. Appl. Phys. 98, 073502 (2005).
http://dx.doi.org/10.1063/1.2064308
71.
71. D. Li, Y. H. Leung, A. B. Djurišić, Z. T. Liu, M. H. Xie, S. L. Shi, S. J. Xu and W. K. Chan, Appl. Phys. Lett. 85, 1601 (2004).
http://dx.doi.org/10.1063/1.1786375
72.
72. C. Klingshirn, phys. stat. sol. (b) 244, 3027 (2007).
http://dx.doi.org/10.1002/pssb.200743072
73.
73. D. Wang, Z. Q. Chen, D. D. Wang, N. Qi, J. Gong, C. Y. Cao, and Z. Tang, J. Appl. Phys. 107, 023524 (2010).
http://dx.doi.org/10.1063/1.3291134
74.
74. G. Kresse and J. Furthmuller, Phys. Rev. B 54, 11169 (1996).
http://dx.doi.org/10.1103/PhysRevB.54.11169
75.
75. P. E. Blochl, Phys. Rev. B 50, 17953 (1994).
http://dx.doi.org/10.1103/PhysRevB.50.17953
76.
76. J. P. Perdew, K. Burke, and M. Ernzerhof, Phys. Rev. Lett. 78, 1396 (1997).
http://dx.doi.org/10.1103/PhysRevLett.78.1396
77.
77. H. J. Monkhorst and J. D. Pack, Phys. Rev. B 13, 5188 (1976).
http://dx.doi.org/10.1103/PhysRevB.13.5188
78.
78. V. R. Saunders et al., Crystal03 User's Manual, University of Torino, Torino, 2003 (www.crystal.unito.it).
79.
79. Y. H. Lu, Z. X. Hong, Y. P. Feng and S. P. Russo, Appl. Phys. Lett. 96, 091914 (2010).
http://dx.doi.org/10.1063/1.3340934
80.
80. C. Kittel, Introduction to Solid State Physics (8th edn New York: Wiley, 2005).
81.
81. J. M. D. Coey, M. Venkatesan, P. Stamenov, C. B. Fitzgerald, and L. S. Dorneles, Phys. Rev. B 72, 024450 (2005).
http://dx.doi.org/10.1103/PhysRevB.72.024450
82.
82. C. Das Pemmaraju and S. Sanvito, Phys. Rev. Lett. 94, 217205 (2005).
http://dx.doi.org/10.1103/PhysRevLett.94.217205
83.
83. G. Bouzerar and T. Ziman, Phys. Rev. Lett. 96, 207602 (2006).
http://dx.doi.org/10.1103/PhysRevLett.96.207602
84.
84. N. H. Hong, J. Sakai, and V. Brize, J. Phys.: Condens. Matter 19, 036219 (2007).
http://dx.doi.org/10.1088/0953-8984/19/3/036219
http://aip.metastore.ingenta.com/content/aip/journal/adva/1/2/10.1063/1.3609964
Loading
View: Figures

Figures

Image of FIG. 1.

Click to view

FIG. 1.

(Color online) Schematic illustration of two approaches towards generating magnetic orders in an oxide host. (a) In reducing growth environments, metal nanoclusters often form due to the strong cohesive force although the transition metal ions are intended to dope randomly into the oxide matrix. (b) As a conceptually different approach, native defects can be purposely generated in the oxide host, and the exhange interaction between local moments at the defect sites may help to establish a long-range ferromagnetic order.

Image of FIG. 2.

Click to view

FIG. 2.

(Color online) XRD patterns of (a) MBE and (b) Sol-gel (SG) ZnO films. Insets show the corresponding AFM images along with the RMS roughness. (c) EDS spectrum of the as-grown SG ZnO film. Inset shows the Zn/O atomic ratios of the as-grown and the Ar annealed SG ZnO films, in comparison with the MBE sample. (d) SIMS depth profiles showing the total counts vs. sputtering depth for all the detected elements in the SG and the MBE samples. Note that all impurity elements show traces well below ten counts.

Image of FIG. 3.

Click to view

FIG. 3.

(Color online) (a) M-H data before subtraction of the substrate contribution measured at 5 and 300 K on the as-grown, the Ar-annealed, the broken ZnO SG samples as well as the ZnO MBE sample. The measurement on the as-grown SG sample was repeated after two month to confirm the reproducibility of data. (b) Corresponding M-H loops after the subtraction of the substrate diamagnetic signals. (c) M-T curves of the SG and the MBE samples measured in the temperature range of 5-380 K. Both the FC and ZFC data are shown. (d) Normalized M-T curve of the SG sample in the extended temperature range of 5-780 K. The high-temperature SQUID data were measured in an oven attached to SQUID.

Image of FIG. 4.

Click to view

FIG. 4.

(Color online) (a) Temperature-dependent resistance of the SG (circles) and MBE (squares) samples. The high temperature data show the thermal activated conduction (green lines), whereas the variable-range-hopping dominates the transport at lower temperature (inset). (b) MR measured on the SG and the MBE ZnO films at 50 and 300 K. Theoretical fittings (green lines) were obtained according to the equation (1) (see the text). (c) Anomalous Hall effect measured in the SG ZnO sample, while it was not observed in the MBE sample with a much weaker magnetization.

Image of FIG. 5.

Click to view

FIG. 5.

(Color online) Temperature dependent PL spectra of (a) SG and (b) MBE ZnO thin films measured in the temperature range of 80-300 K. Inset of (a) shows the room temperature PL data of the Ar-annealed SG ZnO sample in comparison with the as-grown sample.

Image of FIG. 6.

Click to view

FIG. 6.

(Color online) (a) 80 K PL spectra of the SG and the MBE ZnO samples in the enlarged UV region. (b) Temperature-dependent evolution of the UV emission spectra in SG ZnO sample. (c) Integrated intensity of the A0X peak in the SG sample as a function of 1000/T. Inset shows the energy diagram proposed based on the observed defect-related emissions in the SG ZnO sample.

Image of FIG. 7.

Click to view

FIG. 7.

(Color online) Formation energies of various native defects in ZnO under the Zn-rich and the O-rich conditions.

Image of FIG. 8.

Click to view

FIG. 8.

(Color online) (a) Atomic ZnO supercell containing one Zn vacancy. The red and grey balls represent Zn and O atoms, respectively, while the light grey ball is the VZn defect. (b) Corresponding spin up and spin down DOS. For comparison, DOS was also calculated for the ZnO supercell containing an O interstitial as shown in (c). In both (b) and (c), the Fermi levels are indicated by the dashed lines. Insets in (b) and (c) indicate the enlarged view of DOS near the Fermi level.

Image of FIG. 9.

Click to view

FIG. 9.

(Color online) Isosurface plot of the spin density of a Zn34O36 supercell containing two Zn vacancies whose positions are marked by dashed circles. The red small and grey large balls represent O and Zn, respectively.

Loading

Article metrics loading...

/content/aip/journal/adva/1/2/10.1063/1.3609964
2011-06-29
2014-04-19

Abstract

To shed light on the mechanism responsible for the weak ferromagnetism in undoped wide band gap oxides, we carry out a comparative study on ZnOthin films prepared using both sol-gel and molecular beam epitaxy(MBE) methods. Compared with the MBE samples, the sol-gel derived samples show much stronger room temperature ferromagnetism with a magnetic signal persisting up to ∼740 K, and this ferromagnetic order coexists with a high density of defects in the form of zincvacancies. The donor-acceptor pairs associated with the zincvacancies also cause a characteristic orange-red photoluminescence in the sol-gel films. Furthermore, the strong correlation between the ferromagnetism and the zincvacancies is confirmed by our first-principles density functional theory calculations, and electronic band alteration as a result of defect engineering is proposed to play the critical role in stabilizing the long-range ferromagnetism.

Loading

Full text loading...

/deliver/fulltext/aip/journal/adva/1/2/1.3609964.html;jsessionid=2hkgh22c49icr.x-aip-live-01?itemId=/content/aip/journal/adva/1/2/10.1063/1.3609964&mimeType=html&fmt=ahah&containerItemId=content/aip/journal/adva
true
true
This is a required field
Please enter a valid email address
752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd
Scitation: Defect-induced magnetism in undoped wide band gap oxides: Zinc vacancies in ZnO as an example
http://aip.metastore.ingenta.com/content/aip/journal/adva/1/2/10.1063/1.3609964
10.1063/1.3609964
SEARCH_EXPAND_ITEM