ELECTRICAL RESISTIVITY OF GRAPHITE MATERIALS

L. I. Berger

At normal conditions, the only stable crystallographic modifi-

cation of carbon is graphite. The quasi-stable diamond turns into 
graphite starting from about 1000ºC in the air. In industry, a gra-
phitic material is commonly called either carbon, if it consists of 
small and low-oriented crystallites, or graphite, the material with 
highly ordered structure. In the 1970s, the first carbon filaments 
of about 7 nm in diameter were grown by Morinobu Endo at the 
University of Orleans, France, by the vapor-growth technique. 
In 1985, Sir Harold Walter Kroto of Sussex University, UK, and 
Richard E. Smalley and co-workers at Rice University discovered 
spherical carbon molecules, C

60

 (or C60), consisting of combina-

tions of carbon atoms organized into hexagons and pentagons, 
named  buckminsterfullerenes  or  fullerenes  and possessing very 
promising mechanical and electrical properties. In 1991, Sumio 
Iijima, NEC Labs, Japan, and David S. Bethune, IBM Almaden 
Labs, observed the carbon atomic groups in the form of tubes 
capped by halves of the fullerene molecules and formed on the 
cathodes of carbon arc devices. The length of the tubes could be 
up to tens of micrometers and the diameter, naturally, is equal 
to that of the fullerene molecule. These tubes, called nanotubes, 
may be single wall (SWNT) or consist of several concentric tubes 
with a common axis (multi-walled nanotubes, MWNT). Two-di-
mensional  graphene is another crystallographic modification of 

graphite (Saroj Nayak, Rensselaer U., 2004) that is a flat hexagonal 
network of carbon atoms with a thickness equal to the carbon 
atom size. The nanotube may be considered as formed by strips 
of graphenes turned into a cylinder. The character of the electrical 
conductivity (metallic or semiconductive) of a SWNT depends 
on orientation of the carbon hexagons of the nanotube surface 
regarding its axis (the chiral angle [Ref. 1]). The following table 
contains some typical data on electrical and electronic properties 
of graphite materials. 

References

  1.  M. S. Dresselhaus, G. Dresselhaus, and Ph. Avouris (Eds.), Carbon 

Nanotubes. Synthesis, Structure, Properties, and Applications, 
Springer-Verlag, 2001.

  2.  ESPI Metals Catalog, 2007.
  3.  SPI Supplies Catalog, 2007.
  4.  F. L. Vogel, J. Mater. Sci., 12, 982–986, 1977.
  5.  K. S. Novoselov et al., Nature, 438, 197–200, 2005.
  6.  Y. Zhang et al., Nature, 438, 201–204, 2005.
  7.  N. Tombros et al., Nature, 448, 571–574, 2007.
  8.  H. Dai, in Ref. 1, pp. 29–53.
  9.  CTI Carbon Nanotube Cat., 2007.
 10.  L. Matija et al., Sci. Forum, 413, 49–52, 2003.

Material

Electrical resistivity ρ at R. T. 

mΩ cm [μΩ inch]

Energy gap at R. T. 

eV

Electron mobility 

cm

2

/V s

(1/ρ)dρ/dt near R. T. 

10

–4 

°C

–1

Ref.

Bulk graphite

Electromet graphite

1.90 [750]

–5

2

Electro graphite

1.60 [630]

–5

2

Aeromet graphite

1.47 [580]

–5

2

ESPI Superconductive

1.75 [690]

–5

2

Radioelectronics data

30 [11,800]

–5.6

3

Highly ordered pyrolytic graphite

Parallel 0.04 [15.7]

3

Across 150 [59000]

Single crystal graphite, normal to c-axis

1•10

-6

4

Graphenes

n-Graphene

≈5 (М); ≈10 (Г)

c

10

6

5,6

p-Graphene

10

4

7

Carbon nanotubes

Metallic SWNT

12 kΩ

a

1

Semiconducting SWNT

0.7 – 0.9

b

128

d

1

MWNT

10

2

9

Carbon fullerenes

Fullerene (C

60

)

10

12

1.95

10

a 

Minimum resistance of individual nanotubes [Ref. 8]

b 

Est. from Ref. 1, p. 47

c 

Est. from Ref. 1, p. 116

d 

Est. from Ref. 1, p. 179.

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