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Author Rath, Chandana ♦ Singh, Sonal ♦ Mallick, P. ♦ Pandey, D. ♦ Lalla, N. P. ♦ Mishra, N. C.
Source IACS Kolkata
Content type Text
Publisher Indian J. Phys.
File Format PDF
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Physics
Subject Keyword Dilute magnetic semiconductor ♦ Nanoparticles ♦ Susceptibility ♦ ZnO
Abstract Ferromagentic semiconductors have been actively pursued because of their potential as spinpolarized carrier sources and easy integration into semiconductor technology. One such material, ZnO has beenshown to be a potential Diluted Magnetic Semiconductor (DMS). The appearance of ferromagnetism, however,is found to be sensitive to the processing conditions. We report synthesis of ZnO nanoparticles of size ~20 nmby a simple co-precipitation technique using metal nitrates and NaOH as precipitant. The particles are selforganisedand reveal single crystalline behaviour in electron diffraction pattern. Incorporation of Co in ZnO matrixleads not only to the reduction in crystallite size but also to the modification of the structure. At 5% Co, theparticles are highly textured. The particles also aggregate and the aggregated mass have nearly rectangularshape as seen through TEM. Increasing Co to 10%, results into further reduction of particle size and the particlesself organize in a line, which looks like nanofibers. This alignment of particles increases by increasing the Cocontent further. This type of growth of nanofibers above Co ≥ 10% is well correlated with the anisotropic peakbroadening observed in the XRD spectra. In addition, Co substitute Zn site up to 20% without showing any extraphase in XRD spectra as compared to 7 to 10% in case of bulk. Transport and magnetic studies indicate thatconductivity increases with increasing Co content, but carrier mediated ferromagnetism is absent down to 10 K.
Education Level UG and PG
Learning Resource Type Article
Journal Indian J Phys
Volume Number 83
Issue Number 4
Page Count 7
Starting Page 415
Ending Page 421