Carbogenic Nanodots: Photoluminescence and Room-Temperature Ferromagnetism

Authors

  • Sachchidanand Srivastava,

    1. Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016 (India), Fax: (+91) 512-2597080
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  • Prof. Namdeo S. Gajbhiye

    Corresponding author
    1. Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016 (India), Fax: (+91) 512-2597080
    • Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016 (India), Fax: (+91) 512-2597080
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Abstract

Herein, blue fluorescent carbogenic nanodots (CNDs) with room-temperature ferromagnetism were synthesized by thermal decomposition of organic precursors at different temperatures. Photoluminescence (PL) studies show excitation-wavelength-dependent emission properties and PL excitation (PLE) studies confirm the triplet ground state of carbene at the zigzag edge as the fluorescent center. Room-temperature magnetic studies reveal the ferromagnetic nature of CNDs and temperature-dependent studies show the presence of an antiferromagnetic phase along with a ferromagnetic phase below 50 K. EPR studies reveal the presence of conduction electrons and localized spins with different g factors. Localized spins at zigzag edges are the origin of the unconventional magnetic behavior, whereas exchange coupling between conduction and localized spins are responsible for long-range magnetic ordering.

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