Influence of Proton Irradiation on Defect and Magnetism of Yb-doped ZnO Dluted Magnetic Semiconductor Thin Films

doi:10.15541/jim20170420

Abstract

Abstract:

Yb-doped ZnO thin films were prepared by inductively coupled plasma enhanced physical vapor deposition method, the as-deposited Zn_0.985Yb_0.015O thin films were irradiated by proton with different doses. X-ray diffraction, X-ray photoelectron spectroscopy, positron annihilation spectroscopy, and magnetic property measurement were used to study the defect and ferromagnetism. The magnetic property measurement results indicate that the saturation magnetization of Zn_0.985Yb_0.015O thin films increases with the increment of irradiation doses, and reaches the maximum value at 6×10¹⁵ ions/cm². With the further increase in irradiation doses, the saturation magnetization decreases. The positron annihilation measurement reveals that Zn vacancy-related defects dominate in proton irradiated Zn_0.985Yb_0.015O thin films. It is found that dependency of saturation magnetization on irradiation doses exhibits the same behavior with the amount of Zn vacancy-related defects on irradiation doses. It is experimentally demonstrated that the ferromagnetism of proton irradiated Yb-doped ZnO thin films is mainly influenced by Zn vacancy- related defects.

Key words: Yb-doped ZnO, proton irradiation, diluted magnetic semiconductor, ferromagnetism

CLC Number:

O474

CHEN Wei-Bin, LIU Xue-Chao, ZHUO Shi-Yi, CHAI Jun, SHI Er-Wei. Influence of Proton Irradiation on Defect and Magnetism of Yb-doped ZnO Dluted Magnetic Semiconductor Thin Films[J]. Journal of Inorganic Materials, 2018, 33(8): 903-908.

Figures/Tables 6

Fig. 1 (a) M-H curves of Zn0.985Yb0.015O thin films afterbemg irradiated by different proton doses and (b) saturation magnetization of Zn0.985Yb0.015O thin films after irradiation by different proton doses

Fig. 2 AFM images of Zn0.985Yb0.015O films after irradiated by different proton doses(a) Unirrated; (b) 1 × 1014 ions/cm2; (c) 8 × 1014 ions/cm2; (d) 6 × 1015 ions/cm2; (e) 1 × 1016 ions/cm2; (f) 4 × 1016 ions/cm2

Fig. 3 XRD patterns of Zn0.985Yb0.015O thin films after irradiation by different proton doses

Table 1 Calculated parameters according to (002) diffraction peak of Zn0.985Yb0.015O thin films after irradiation by different proton doses

Parameter/dose (ions/cm²)	0	1×10¹⁴	8×10¹⁴	6×10¹⁵	1×10¹⁶	4×10¹⁶
2θ/(°)	34.222	34.104	34.163	34.163	34.241	34.300
c/nm	0.52360	0.52536	0.52448	0.52448	0.52332	0.52246
FWHM/(°)	0.760	0.741	0.737	0.753	0.700	0.677
D/nm	109.37	112.14	112.76	110.37	118.75	122.80

Fig. 4 XPS spectrum of Zn0.985Yb0.015O thin film after irradiation at a proton dose of 1×1014 ions/cm2 with the inset showing high-resolution XPS spectrum of Yb-4d

Fig. 5 (a) Positron annihilation spectroscopy, (b) dependency of S parameter on the irradiation dose with the positron energy of 14 keV and (c) S-W curves of Zn0.985Yb0.015O thin films after irradiation by different proton doses

References 21

[1]	GUPTA S, FENWICK W E, MELTON A,et al .MOVPE growth of transition-metal-doped GaN and ZnO for spintronic applications. Journal of Crystal Growth, 2008, 310(23): 5032-5038.
[2]	XIONG Z, LIU X C, ZHUO S Y,et al .. Influence of Ga doping on the Cr valence state and ferromagnetism in Cr: ZnO films. Applied Physics Letters,2013,102(2): 022414-1-4.
[3]	VENKATESH S, FRANKLIN J B, RYAN M P ,et al. Defect-band mediated ferromagnetism in Gd-doped ZnO thin films.Journal of Applied Physics, 2015,117(1): 013913-1-5.
[4]	FUKUMURA T, JIN Z, KAWASAKI M ,et al. Magnetic properties of Mn-doped ZnO.Applied Physics Letters,2011,78(7): 958-960.
[5]	LIU X C, SHI E W, ZHANG H W,et al.Recent progress in developing ZnO-based thin films of diluted magnetic semiconductors.Journal of Inorganic Materials, 2006, 21(3): 513-520.
[6]	DAI J F, MENG C C LI Q. First-principles study on the magnetism of Mn and Co codoped ZnO.Physica B-Condensed Matter,2013, 409: 5-9.
[7]	MA X. The magnetic properties of Gd doped ZnO nanowires. Thin Solid Films, 2012,520(17): 5752-5755.
[8]	CHEN H M, LIU X C, ZHUO S Y, ,et al.Zinc vacancy and erbium cluster jointly promote ferromagnetism in erbium-doped ZnO thin film.AIP Advances, 2014,4(4): 047121-1-7.
[9]	LI F, LIU X C, ZHOU R W, ,et al. Strong correlation between oxygen vacancy and ferromagnetism in Yb-doped ZnO thin films.Journal of Applied Physics, 2014,116(24): 243910-1-6.
[10]	WERNER Z, GOSK J, TWARDOWSKI A,et al. A comparison of the magnetic properties of radiation damaged or Co implanted ZnO single crystals.Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2015,384: 174-178.
[11]	MISHRA D K, MOHAPATRA J, MAHATO B ,et al. Effect of 1.2 MeV argon ions irradiation on magnetic properties of ZnO.Applied Surface Science, 2013,282: 954-959.
[12]	WANG H M, SIMMONDS M C, RODENBURG J M.Manufacturing of YbAG coatings and crystallisation of the pure and Li2O-doped Yb2O3-Al2O3 system by a modified Sol-Gel method.Materials Chemistry and Physics, 2003, 77(3): 802-807.
[13]	AURET F D, GOODMAN S A, HAYES M ,et al. Electrical characterization of 1.8 MeV proton-bombarded ZnO. Applied Physics Letters2001,79(19): 3074-3076.
[14]	GU Q L, CHEUNG C K, LING C C ,et al. Au/n-ZnO rectifying contact fabricated with hydrogen peroxide pretreatment.Journal of Applied Physics, 2008,103(9): 093706-1-8.
[15]	ZHANG B Y, YAO B, LI Y F ,et al. Evidence of cation vacancy induced room temperature ferromagnetism in Li-N codoped ZnO thin films.Applied Physics Letters, 2011,99(18): 182503-1-3.
[16]	KOHAN A F, CEDER G, MORGAN D ,et al. First-principles study of native point defects in ZnO.Physical Review B, 2000,61(22): 15019-15027.
[17]	NING S, ZHAN P, WANG W P, ,et alDefect characterization and magnetic properties in undoped ZnO thin film annealed in a strong magnetic field. Chinese Physics B,2014,23(12): 127503-1-6.
[18]	CHEN Z Q, WANG S J, MAEKAWA M,et al .Thermal evolution of defects in as-grown and electron-irradiated ZnO studied by positron annihilation.Physical Review B, 2007,75(24): 245206-1-9.
[19]	LISZKAY L, CORBEL C, BAROUX L ,et al. Positron trapping at divacancies in thin polycrystalline CdTe films deposited on glass Applied Physics Letters, 1994,64(11): 1380-1382.
[20]	CHEN Z Q, ATSUO K. Vacancy-type defects induced by He-implantation in ZnO studied by a slow positron beam. Acta Physica Sinica, 2006,55(8): 4353-4357.
[21]	ZHOU R W, LIU X C, WANG H J ,et al. Ferromagnetism in proton irradiated 4H-SiC single crystal.AIP Advances, 2015,5(4): 047146-1-6.