Mn2+-induced substitutional structural changes in ZnS nanoparticles as observed from positron annihilation studies

    Authors

    S. Biswas; S. Kar; S. Chaudhuri;P. M. G. Nambissan

    Comments

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    Abbreviated Journal Title

    J. Phys.-Condes. Matter

    Keywords

    MAGNETIC-PROPERTIES; LIFETIME; SPECTRA; Physics, Condensed Matter

    Abstract

    Zinc sulfide nanoparticles doped with different concentrations of manganese ions (Mn2+) were synthesized at various temperatures to investigate the effects of substitution and the associated defect evolution. Positron lifetime and Doppler broadening measurements were used as probes. The initial stage of defect recovery was dominated by the occupation of Zn2+ vacancies by Mn2+ ions, bringing in characteristic changes in the positron lifetimes, intensities and Doppler broadened lineshape parameters. Detailed analyses considering the presence of one and two types of defects were carried out to identify the type of defects which trap positrons at the different dopant concentrations. Electron paramagnetic resonance studies indicated increased Mn-Mn interaction and the formation of Mn clusters with further doping. The results are in striking contrast to those for nanorods, where vacancy recombination transformed their interior into regions free of defects.

    Journal Title

    Journal of Physics-Condensed Matter

    Volume

    20

    Issue/Number

    23

    Publication Date

    1-1-2008

    Document Type

    Article

    Language

    English

    First Page

    10

    WOS Identifier

    WOS:000256172800028

    ISSN

    0953-8984

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