c-axis resistivity ofMoCl5graphite intercalation compounds

Magnetic-field-induced superconductor–metal-insulator transitions in bismuth metal graphite

“…In BiCl 3 GIC, the ratio of c-axis resistivity ρ c to the in-plane resistivity ρ a (∆ = ρ c /ρ a ) at room temperature is (7.4 -4.9) × 10 3 , 11 suggesting that virtually all π-electrons are directionally localized; i.e., they can move freely along the graphite basal planes, but are unable to diffuse across the stack of layers. 12 Such a large ratio ∆ is due to the insulating BiCl 3 layer sandwiched between the adjacent graphite layers. There is no overlapping of the wave functions over nearest neighbor graphite layers.…”

Electrical Conductivity and Conduction ESR in Incommensurate Phase of Graphite Intercalation Compounds C5nHNO3

“…The contributions of these mechanisms to s c depend on the nature of intercalate, stage of compounds, temperature and pressure [6,[15][16][17][18][19][20]. This is the reason why the magnitude and sign of the temperature coefficient of conductivity ds c /dT for these compounds depends both on GIC structure and on external experimental conditions [6,[15][16][17][18][19][20].…”

“…In the case of the lowest stage compounds (n ¼ 1, 2) the main contribution to s c is from the mechanism of charge transfer through the defect-mediated narrow high-conductivity paths (channels) [6,[15][16][17][18][19][20]. According to Sugihara and coworkers [19,20] the value of this contribution to s c is described as…”

“…where V 0 is the matrix element of the scattering potential, N c is the number of conduction paths per unit cell, m * is the effective mass of carriers, d I is the distance between nearest neighbour layers with an intervening intercalate layer, e is the electron charge, h is Planck's constant, and G/ h is the sum of the relaxation rates due to phonon and impurity scattering: G/ h ¼ G ph / h + G I / h. At high temperatures it is possible to consider G/ h with good accuracy to be equal to the relaxation rate of current carriers in the graphite basal plane G a / h associated with the s a [19,20].…”

“…In the literature, for the explanation of the s c peculiarities, including the abovementioned ones, alternative models postulating its band [10][11][12][13][14] or non-band [6,[15][16][17][18][19][20] origin have been suggested. Therefore, search for and study of new properties of s c in acceptor GICs, which clarify its origin, are important steps towards creating a theory of the c-axis charge transport in these synthetic metals.…”