SPIN RESONANCE OF CHARGE CARRIERS IN GRAPHITE

摘要: The observations reported here of the electron spin resonance in quite perfect single crystals graphite clearly establish that arises from mobile charge carriers. line shape is Dysonian form which characteristic conduction metals. intensity agrees, both absolute magnitude and temperature dependence, with values calculated band model by J. W. McClure. g-value shows a remarkably large anisotropy depends strongly on position Fermi level respect to edge. At room pure graphite, g varies 2.0026 ± 0.0002 2.0495 as magnetic field shifted perpendicular parallel c-axis. increases decreasing temperature; g‖ becomes 2.127 at 77°K while g⊥ remains constant. width few gauss (T2 = 2.0 × 10−8 sec) extremely narrow comparison shifts caused changes temperature. This indicates for states strong function wave vector narrowed an averaging process k-space. similar occurs motional exchange narrowing.