Thermal ionization induced metal-semiconductor transition and room temperature ferromagnetism in trivalent doped ZnO codoped with lithium

被引：6
作者：
Sivagamasundari, A. [1 ]
Chandrasekar, S. [1 ]
Pugaze, R. [1 ]
Rajagopan, S. [2 ]
Kannan, R. [1 ]
机构：
[1] Pondicherry Engn Coll, Dept Phys, Pondicherry 605014, India
[2] Pondicherry Engn Coll, Dept Chem, Pondicherry 605014, India
来源：
JOURNAL OF APPLIED PHYSICS | 2014年 / 115卷 / 09期
关键词：
OPTICAL-TRANSITIONS; ENERGY; FILMS; GAP;
D O I：
10.1063/1.4867036
中图分类号：
O59 [应用物理学];
学科分类号：
摘要：
Thermal ionization induced metallic to semiconductor (MST) transition occurring at 460K for Zn0.97Al0.03O, 463K for Zn0.94Al0.03Li0.03O, and 503K for Zn0.91Al0.03Li0.03Mn0.03O has been found in the sol-gel synthesized (using hexamethylenetetramine), trivalent doped (Al, Mn) ZnO codoped with lithium. Increase in the thermally ionized carrier concentration due to Al doping is responsible for near band edge (NBE) peak shift causing Fermi level to move into conduction band making it metallic consistent with resistivity results. Free carrier (thermally activated) neutralization with ionized donor is responsible for semiconducting nature, which is supported from the free carrier screening produced energy shift in the NBE of photoluminescence peak. Furthermore, independently band gap shrinkage is also obtained from UV-Visible studies confirming localization induced MST. An anti-correlation is found between defect density (DLE) and room temperature ferromagnetism (RTFM) indicating intrinsic defects are not directly responsible for RTFM. (C) 2014 AIP Publishing LLC.
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页数：7
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  • [1] Study of optical properties of some sol-gel derived films of ZnO
    Bandyopadhyay, S
    Paul, GK
    Sen, SK
    [J]. SOLAR ENERGY MATERIALS AND SOLAR CELLS, 2002, 71 (01) : 103 - 113
  • [2] Bates L.F., 1969, BIOGRAPHICAL MEMOIRS, V15, P201
  • [3] Role of deep and shallow donor levels on n-type conductivity of hydrothermal ZnO
    Brochen, S.
    Granier, C.
    Feuillet, G.
    Pernot, J.
    [J]. APPLIED PHYSICS LETTERS, 2012, 100 (05)
  • [4] Defects induced ferromagnetism in Mn doped ZnO
    Chattopadhyay, S.
    Neogi, S. K.
    Sarkar, A.
    Mukadam, M. D.
    Yusuf, S. M.
    Banerjee, A.
    Bandyopadhyay, S.
    [J]. JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 2011, 323 (3-4) : 363 - 368
  • [5] Room temperature ferromagnetism in nanostructured ZnO-Al system
    Chen, S. J.
    Suzuki, K.
    Garitaonandia, J. S.
    [J]. APPLIED PHYSICS LETTERS, 2009, 95 (17)
  • [6] Chen SS, 2012, PLOS ONE, V7, DOI [10.1371/journal.pone.0036784, 10.1371/journal.pone.0049275, 10.1371/journal.pone.0045763, 10.1371/journal.pone.0050456]
  • [7] Effects of Growth Temperature on the Properties of ZnO Thin Films Grown by Radio-frequency Magnetron Sputtering
    Cho, Shinho
    [J]. TRANSACTIONS ON ELECTRICAL AND ELECTRONIC MATERIALS, 2009, 10 (06) : 185 - 188
  • [8] Charge-transfer ferromagnetism in oxide nanoparticles
    Coey, J. M. D.
    Wongsaprom, Kwanruthai
    Alaria, J.
    Venkatesan, M.
    [J]. JOURNAL OF PHYSICS D-APPLIED PHYSICS, 2008, 41 (13)
  • [9] Ferromagnetism in defect-ridden oxides and related materials
    Coey, J. M. D.
    Stamenov, P.
    Gunning, R. D.
    Venkatesan, M.
    Paul, K.
    [J]. NEW JOURNAL OF PHYSICS, 2010, 12
  • [10] Donor impurity band exchange in dilute ferromagnetic oxides
    Coey, JMD
    Venkatesan, M
    Fitzgerald, CB
    [J]. NATURE MATERIALS, 2005, 4 (02) : 173 - 179
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