The role of oxygen vacancies in magnetism of CoxTi1-xO2-δ films on Si(001) prepared by sol-gel method

被引：17
作者：
Liu, L. F. [1 ]
Kang, J. F. [1 ]
Wang, Y. [1 ]
Tang, H. [1 ]
Kong, L. G. [1 ]
Zhang, X. [1 ]
Han, R. Q. [1 ]
机构：
[1] Peking Univ, Inst Microelect, Beijing 100871, Peoples R China
来源：
SOLID STATE COMMUNICATIONS | 2006年 / 139卷 / 06期
基金：
高等学校博士学科点专项科研基金; 中国国家自然科学基金;
关键词：
ferromagnetism; co-doped TiO2; sol-gel method;
D O I：
10.1016/j.ssc.2006.06.022
中图分类号：
O469 [凝聚态物理学];
学科分类号：
070205 ;
摘要：
CoxTi1-xO2-delta films have been prepared on Si(001) substrates by sol-gel method. When heat treated in air, CoxTi1-xO2-delta films are nonferromagnetic at room temperature. However, after further vacuum annealing or hydrogenation, CoxTi1-xO2-delta films show room-temperature ferromagnetism (RTFM). When the vacuum annealed CoxTi1-xO2-delta films are reheated in air, the magnetic moments of the films strongly reduce. After these films are vacuum annealed once again, the magnetic moments are greatly enhanced, confirming the role of vacuum annealing in ferromagnetism of CoxTi1-xO2-delta films. The x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS) and measurements of magnetization (M) vs temperature (T) fail to detect Co clusters in the vacuum annealed and the hydrogenated CoxTi1-xO2-delta films. Oxygen vacancies are formed in CoxTi1-xO2-delta films after vacuum annealing and hydrogenation, determined by XRD and XPS measurements. These results indicate that oxygen vacancies created by vacuum annealing and hydrogenation play an important role in the generation of RTFM in CoxTi1-xO2-delta films. (c) 2006 Elsevier Ltd. All rights reserved.
引用
收藏
页码：263 / 267
页数：5
相关论文
共 23 条
  • [1] Anisotropy of ferromagnetism in Co-implanted rutile
    Akdogan, N
    Rameev, BZ
    Dorosinsky, L
    Sozeri, H
    Khaibullin, RI
    Aktas, B
    Tagirov, LR
    Westphalen, A
    Zabel, H
    [J]. JOURNAL OF PHYSICS-CONDENSED MATTER, 2005, 17 (34) : L359 - L366
  • [2] Epitaxial growth and properties of MBE-grown ferromagnetic Co-doped TiO2 anatase films on SrTiO3(001) and LaAlO3(001)
    Chambers, SA
    Wang, CM
    Thevuthasan, S
    Droubay, T
    McCready, DE
    Lea, AS
    Shutthanandan, V
    Windisch, CF
    [J]. THIN SOLID FILMS, 2002, 418 (02) : 197 - 210
  • [3] Ferromagnetism in Fe-doped SnO2 thin films
    Coey, JMD
    Douvalis, AP
    Fitzgerald, CB
    Venkatesan, M
    [J]. APPLIED PHYSICS LETTERS, 2004, 84 (08) : 1332 - 1334
  • [4] Theoretical study of magnetism in transition-metal-doped TiO2 and TiO2-δ -: art. no. 184425
    Errico, LA
    Rentería, M
    Weissmann, M
    [J]. PHYSICAL REVIEW B, 2005, 72 (18)
  • [5] Epitaxial growth of ferromagnetic Co:TiO2 thin films by co-sputtering
    Han, GC
    Wu, YH
    Tay, M
    Li, KB
    Guo, ZB
    Chong, TC
    [J]. JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 2004, 268 (1-2) : 159 - 164
  • [6] Hong N. H., 2004, J APPL PHYS, V95, P7378
  • [7] Formation of Co nanoclusters in epitaxial Ti0.96Co0.04O2 thin films and their ferromagnetism
    Kim, DH
    Yang, JS
    Lee, KW
    Bu, SD
    Noh, TW
    Oh, SJ
    Kim, YW
    Chung, JS
    Tanaka, H
    Lee, HY
    Kawai, T
    [J]. APPLIED PHYSICS LETTERS, 2002, 81 (13) : 2421 - 2423
  • [8] Ferromagnetism induced by clustered Co in Co-doped anatase TiO2 thin films -: art. no. 017401
    Kim, JY
    Park, JH
    Park, BG
    Noh, HJ
    Oh, SJ
    Yang, JS
    Kim, DH
    Bu, SD
    Noh, TW
    Lin, HJ
    Hsieh, HH
    Chen, CT
    [J]. PHYSICAL REVIEW LETTERS, 2003, 90 (01)
  • [9] Oxygen-vacancies-related room-temperature ferromagnetism in polycrystalline bulk co-doped TiO2
    Kong, LG
    Kang, JF
    Wang, Y
    Sun, L
    Liu, LF
    Liu, XY
    Zhang, X
    Han, RQ
    [J]. ELECTROCHEMICAL AND SOLID STATE LETTERS, 2006, 9 (01) : G1 - G3
  • [10] Synthesis and characterization of titania films on Mo(110)
    Lai, X
    Guo, Q
    Min, BK
    Goodman, DW
    [J]. SURFACE SCIENCE, 2001, 487 (1-3) : 1 - 8
123