Open AccessDifference in electric conduction of monocrystal and polycrystal graphite
Author(s) -
Zhiming Wang,
Xu Qing-Yu,
Shiyuan Zhang,
Xing Ding-Yu,
Du You-Wei
Publication year - 2007
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.56.3464
Subject(s) - graphite , materials science , condensed matter physics , magnetoresistance , thermal conduction , scattering , coulomb , insulator (electricity) , magnetic field , electrical resistivity and conductivity , electric field , electron , composite material , physics , optics , quantum mechanics
In this paper, we report the difference in electric conduction of monocrystal and polycrystal graphite. Under a magnetic field of 8.15T, the positive magnetoresistance ratio of monocrystal and polycrystal graphite samples are found to be 69400%, 170% respectively at 4.5K. The polycrystal graphite presents accordingly the insulator-like character in a wide interval of temperature under 0 and 8T applied magnetic field, but the magnetic-field-correlated semimetal-insulator-like Transition has been reported for the monocrystal graphite (highly oriented pyrolitic graphite, HOPG). On analysis, it is revealed that large difference in electric conduction originates predominantly from the Coulomb interaction in HOPG graphite layers in contrast with the crystal interface scattering in the polycrystal graphite.