[1] Morin F J 1959 Phys. Rev. Lett. 3 34
[2] Lopez R, Boatner L A, Haynes T E, Haglund Jr R F, Feldman L C 2004 Appl. Phys. Lett. 85 1410
[3] Kim H T, Lee Y W, Kim B J, Chae B G, Yun S J, Kang K Y, Han K J, Yee K J, Lim Y S 2006 Phys. Rev. Lett. 97 266401
[4] Wen Q Y, Zhang H W, Yang Q H, Xie Y X, Chen K, Liu Y L 2010 Appl. Phys. Lett. 97 021111
[5] Wang X J, Liu Y Y, Li D H, Feng B H, He Z W, Qi Z 2013 Chin. Phys. B 22 066803
[6] Sun D D, Chen Z, Wen Q Y, Qiu D H, Lai W E, Dong K, Zhao B H, Zhang H W 2013 Acta Phys. Sin. 62 017202 (in Chinese) [孙丹丹, 陈智, 文岐业, 邱东鸿, 赖伟恩, 董凯, 赵碧辉, 张怀武 2013 物理学报 62 017202]
[7] Stefanovich G, Pergament A, Stefanovich D 2000 J. Phys.: Condens. Matter 12 8837
[8] Seo G, Kim B -J, Ko C, Cui Y, Lee Y W, Shin J H, Ramanathan S, Kim H T 2011 IEEE Electron Device Lett. 32 1582
[9] Ha S D, Zhou Y, Fisher C J, Ramanathan S, Treadway J P 2013 J. Appl. Phys. 113 184501
[10] Kanki T, Hotta Y, Asakawa N, Kawai T, Tanaka H 2010 Appl. Phys. Lett. 96 242108
[11] Lee Y W, Kim B J, Lim J W, Yun S J, Choi S, Chae B G, Kim G, Kim H T 2008 Appl. Phys. Lett. 92 162903
[12] Zhao Y, Lee J H, Zhu Y H, Nazari M, Chen C H, Wang H Y, Bernussi A, Holtz M, Fan Z Y 2012 J. Appl. Phys. 111 053533
[13] Wang C L, Tian Z, Xing Q R, Gu J Q, Liu F, Hu M L, Chai L, Wang Q Y 2010 Acta Phys. Sin. 59 7857 (in Chinese) [王昌雷, 田震, 邢岐荣, 谷建强, 刘丰, 胡明列, 柴路, 王清月 2010 物理学报 59 7857]
[14] Li J, Dho J 2011 Appl. Phys. Lett. 99 231909
[15] Luo Z F, Wu Z M, Xu X D, Wang T, Jiang Y D 2010 Chin. Phys. B 19 106103
[16] Lee M J, Park Y, Suh D S, Lee E H, Seo S, Kim D C, Jung R, Kang B S, Ahn S E, Lee C B, Seo D H, Cha Y K, Yoo I K, Kim J S, Park B H 2007 Adv. Mater. 19 3919
[17] Zhou Y, Chen X, Ko C, Yang Z, Ramanathan S 2013 IEEE Electron Device Lett. 34 220
[18] Okimura K, Suruz Mian Md 2012 J. Vac. Sci. Technol. A 30 051502
[19] Grbovic D, Lavrik N V, Rajic S, Datskos P G 2008 J. Appl. Phys. 104 054508
[20] Ji Y D, Pan T S, Bi Z, Liang W Z, Zhang Y, Zeng H Z, Wen Q Y, Zhang H W, Jia Q X, Lin Y 2012 Appl. Phys. Lett. 101 071902
[21] Narayan J, Bhosle V M 2006 J. Appl. Phys. 100 103524
[22] Kim H T, Chae B G, Youn D H, Maeng S L, Kim G, Kang K Y, Lim Y S 2004 New J. Phys. 6 52
[23] Leroy J, Crunteanu A, Bessaudou A, Cosset F, Champeaux C, Orlianges J C 2012 Appl. Phys. Lett. 100 213507
[24] Crunteanu A, Givernaud J, Leroy J, Mardivirin D, Champeaux C, Orlianges J C, Catherinot A, Blondy P 2010 Sci. Technol. Adv. Mater. 11 065002
[25] Ruzmetov D, Gopalakrishnan G, Deng J, Narayanamurti V, Ramanathan S 2009 J. Appl. Phys. 106 083702
[26] Ko C, Ramanathan S 2008 Appl. Phys. Lett. 93 252101