Observation of Room Ferromagnetism in Cu-Implanted Crystal ZnO
LI Tian-Jing1, LI Gong-Ping1, GAO Xing-Xin1, CHEN Jing-Sheng2
1School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 2Department of Material Science and Engineering, National University Singapore, Singapore 119260, Singapore
Observation of Room Ferromagnetism in Cu-Implanted Crystal ZnO
LI Tian-Jing1, LI Gong-Ping1, GAO Xing-Xin1, CHEN Jing-Sheng2
1School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 2Department of Material Science and Engineering, National University Singapore, Singapore 119260, Singapore
Ion implantation technique is used to study the magnetic properties of Cu-doped ZnO. The room temperature ferromagnetism in the Cu-implanted ZnO samples is observed. From the photoluminescence spectrum of implanted samples we observe a broad green emission around 510 nm, which is related to defects in the samples. X-ray photoelectron spectroscopy measurement shows that Cu ions are in the mixed oxidation state of +1 or +2 and substitute for the Zn2+ ions of the ZnO matrix. We argue that the ferromagnetism is related to these defects, and the substitution of Cu2+ into Zn2+ sites in crystal ZnO could contribute to the observed ferromagnetism.
Ion implantation technique is used to study the magnetic properties of Cu-doped ZnO. The room temperature ferromagnetism in the Cu-implanted ZnO samples is observed. From the photoluminescence spectrum of implanted samples we observe a broad green emission around 510 nm, which is related to defects in the samples. X-ray photoelectron spectroscopy measurement shows that Cu ions are in the mixed oxidation state of +1 or +2 and substitute for the Zn2+ ions of the ZnO matrix. We argue that the ferromagnetism is related to these defects, and the substitution of Cu2+ into Zn2+ sites in crystal ZnO could contribute to the observed ferromagnetism.
[1] Dietl T 2000 Science 287 1019 [2] Sato K 2000 Jpn. J. Appl. Phys. II 39(6B) 555 [3] Ueda K et al 2001 Appl. Phys. Lett. 79 988 [4] Saeki H 2001 Solid State Commun. 120 439 [5] Peng L et al 2008 Chin. Phys. Lett. 25 1438 [6] Zhou S M et al 2008 Chin. Phys. Lett. 25 4446 [7] Han S J 2002 Appl. Phys. Lett. 81 4212 [8] Selvaraj V and Ohashi N 2007 J. Appl. Phys. 102 014905 [9] Cho Y M et al 2002 Appl. Phys. Lett. 80 3358 [10] Deng J X, Yan S S and Mei L M 2009 Chin. Phys. Lett. 26 027502 [11] Ramachandran S, Tiwari A and Narayan J 2004 Appl. Phys. Lett. 84 5255 [12] Manivannan A et al 2006 J. Appl. Phys. 99 08M110 [13] Maensiri S, Laokul P and Phokha S 2006 J. Magn. Magn. Mater. 305 381 [14] Deka S 2006 Appl. Phys. Lett. 89 032508 [15] Hays J, Thurber A, Reddy K M and Punnoose A 2006 J. Appl. Phys. 99 08M123 [16] Park J H and M Kim G 2004 J. Phys.: Condens. Matter 19 266203 [17] Park M S and Min B I 2003 Phys. Rev. B 68 224436 [18] Chien C H, Chiou S H and Gao G Y 2006 J. Magn. Magn. Mater. 305 275 [19] Huang D et al 2008 Appl. Phys. Lett. 92 182509 [20] Ando K, Saito H and Fukumura T 2001 J. Appl. Phys. 89 7284 [21] Lee H J, Kim B S and Cho C R 2004 Phys. Status Solid B 241 1533 [22] Buchholz D B, Chang R P and Song J H 2005 Appl. Phys. Lett. 87 082504 [23] Ye L H, Freeman A J and Delley B 2006 Phys. Rev. B 73 033203 [24] Shuai M, Liao L and Lu H B 2008 J. Phys. D: Appl. Phys. 41 135010 [25] Norton D P, overberg M E and Pearton S J 2003 Appl. Phys. Lett. 83 5488 [26] Zhou S Q et al 2008 Phys. Rev. B 77 035209 [27] Zhang B, Wei S H and Zunger A 2001 Phys. Rev. B 63 75205 [28] Garces N Y, Wang L, Bai L and Giles N C 2002 Appl. Phys. Lett. 81 622 [29] Mo C M, Li Y H, Liu Y S and Zhang Y 1998 J. Appl. Phys. 83 4389 [30] Lin B and Fu Z 2001 Appl. Phys. Lett. 79 943 [31] Venkatesan M et a 2004 Phys. Rev. Lett. 93 177206 [32] Hsu H S and Huang J C 2006 Appl. Phys. Lett. 88 242507 [33] Lee J H and Choi I H 2007 Appl. Phys. Lett. 90 0302504 [34] Shuai M, Liao L and Lu H B 2008 J. Phys. D: Appl. Phys. 41 135010 [35] Tiwari A and Snure M 2008 Appl. Phys. Lett. 92 062509 [36] Feng X 2004 J. Phys.: Condens. Matter 16 4251 [37] Herng T S et al 2006 J. Appl. Phys. 99 086101
2010, Vol. 27 
