Grain boundary defects-mediated room temperature ferromagnetism in Co-doped ZnO film

被引：21

作者：

Liu, X. J. ^{[1
]}

Zhu, X. Y. ^{[1
,2
]}

Luo, J. T. ^{[1
]}

Zeng, F. ^{[1
]}

Pan, F. ^{[1
]}

机构：

[1] Tsinghua Univ, Dept Mat Sci & Engn, Adv Mat Lab, Beijing 100084, Peoples R China

[2] Natl Key Lab Remfg, Beijing 100072, Peoples R China

来源：

JOURNAL OF ALLOYS AND COMPOUNDS | 2009年 / 482卷 / 1-2期

基金：

中国国家自然科学基金;

关键词：

Diluted magnetic semiconductor; Microstructure; Grain boundaries; Defect; Ferromagnetism; MAGNETIC-PROPERTIES; NANOPARTICLES; NANOCRYSTALS;

D O I：

10.1016/j.jallcom.2009.03.162

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Zn0.97Co0.03O films with and without ZnO buffer layer have been fabricated by magnetron sputtering to investigate the role of grain boundary defects in ferromagnetic ordering in this system. The deposited wurtzite films with (0 0 2) preferred orientation all show intrinsic room temperature ferromagnetism based on the substitutional behavior of Co2+. We found that the ZnO/Co:ZnO film grows in smaller grain size, compared with Co:ZnO film, which leads to the increase in grain boundary defects. Meanwhile the increase in oxygen vacancies is confirmed by Co K-edge X-ray-absorption near-edge spectra and the enhancement of saturated magnetization is observed in ZnO/Co:ZnO film. Hence the most important factor for mediating ferromagnetism is proposed to be grain boundary defects, i.e., oxygen vacancies. Bound magnetic polaron mechanism is adopted to explain the intrinsic origin and the mediative effects of grain boundary defects on ferromagnetism in Co-doped ZnO films. (C) 2009 Elsevier B.V. All rights reserved.

引用

页码：224 / 228

页数：5

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