Carbogenic Nanodots: Photoluminescence and Room-Temperature Ferromagnetism

• Published in: Chemphyschem 2011-10, Vol.12 (14), p.2624-2632
• Main Authors: Srivastava, Sachchidanand, Gajbhiye, Namdeo S.
• Format: Article
• Language: English
• Subjects: carbogenic nanodots; Condensed matter: electronic structure, electrical, magnetic, and optical properties; EPR spectroscopy; Exact sciences and technology; graphene; magnetic properties; Magnetic properties and materials; Magnetic properties of nanostructures; Nanocrystals and nanoparticles; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures; photoluminescence; Physics
• ISSN: 1439-4235; 1439-7641
• DOI: 10.1002/cphc.201100188

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. A spot of blue: Blue‐fluorescent carbogenic nanodots (CNDs) are synthesized by thermal decomposition and their room‐temperature ferromagnetic nature is revealed. 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 (see picture).