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Title: First principles study of magnetism in nanographenes

Abstract

Magnetism in nanographenes (also know as polycyclic aromatic hydrocarbons, or PAHs) are studied with first principles density functional calculations. We find that an antiferromagnetic (AFM) phase appears as the PAH reaches a certain size. This AFM phase in PAHs has the same origin as the one in infinitely long zigzag-edged graphene nanoribbons, namely, from the localized electronic state at the zigzag edge. The smallest PAH still having an AFM ground state is identified. With increased length of the zigzag edge, PAHs approach an infinitely long ribbon in terms of (1) the energetic ordering and difference among the AFM, ferromagnetic (FM), and nonmagnetic (NM) phases and (2) the average local magnetic moment at the zigzag edges. These PAHs serve as ideal targets for chemical synthesis of nanographenes that possess magnetic properties. Moreover, our calculations support the interpretation that experimentally observed magnetism in activated carbon fibers originates from the zigzag edges of the nanographenes.

Authors:
 [1];  [1];  [1]
  1. ORNL
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Center for Nanophase Materials Sciences; Center for Computational Sciences
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
930992
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 127
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 77 NANOSCIENCE AND NANOTECHNOLOGY; NANOSTRUCTURES; DENSITY FUNCTIONAL METHOD; MAGNETIC MOMENTS; MAGNETIC PROPERTIES; MAGNETISM; POLYCYCLIC AROMATIC HYDROCARBONS; SYNTHESIS; ANTIFERROMAGNETISM; FERROMAGNETISM; PHASE TRANSFORMATIONS; ACTIVATED CARBON; CARBON FIBERS

Citation Formats

Jiang, Deen, Sumpter, Bobby G, and Dai, Sheng. First principles study of magnetism in nanographenes. United States: N. p., 2007. Web. doi:10.1063/1.2770722.
Jiang, Deen, Sumpter, Bobby G, & Dai, Sheng. First principles study of magnetism in nanographenes. United States. doi:10.1063/1.2770722.
Jiang, Deen, Sumpter, Bobby G, and Dai, Sheng. Mon . "First principles study of magnetism in nanographenes". United States. doi:10.1063/1.2770722.
@article{osti_930992,
title = {First principles study of magnetism in nanographenes},
author = {Jiang, Deen and Sumpter, Bobby G and Dai, Sheng},
abstractNote = {Magnetism in nanographenes (also know as polycyclic aromatic hydrocarbons, or PAHs) are studied with first principles density functional calculations. We find that an antiferromagnetic (AFM) phase appears as the PAH reaches a certain size. This AFM phase in PAHs has the same origin as the one in infinitely long zigzag-edged graphene nanoribbons, namely, from the localized electronic state at the zigzag edge. The smallest PAH still having an AFM ground state is identified. With increased length of the zigzag edge, PAHs approach an infinitely long ribbon in terms of (1) the energetic ordering and difference among the AFM, ferromagnetic (FM), and nonmagnetic (NM) phases and (2) the average local magnetic moment at the zigzag edges. These PAHs serve as ideal targets for chemical synthesis of nanographenes that possess magnetic properties. Moreover, our calculations support the interpretation that experimentally observed magnetism in activated carbon fibers originates from the zigzag edges of the nanographenes.},
doi = {10.1063/1.2770722},
journal = {Journal of Chemical Physics},
number = ,
volume = 127,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
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