https://doi.org/10.1140/epjb/e2003-00311-4
Electrical conduction in nanostructured carbon and carbon-metal films grown by supersonic cluster beam deposition
1
INFM-Dipartimento di Energetica, Università di Firenze, Via S. Marta 3, 50139 Firenze, Italy
2
INFM-Dipartimento di Fisica, Università di Milano, Via Celoria 16, 20133 Milano, Italy
3
Department of Engineering, Cambridge University, Cambridge, UK
Corresponding author: a pmilani@mi.infn.it
Received:
14
April
2003
Published online:
19
November
2003
We have studied the electrical conduction in nanostructured carbon (ns-C)
films produced by deposition of a supersonic beam of neutral carbon
clusters. The d.c. conduction properties of these films have been measured
in situ during the deposition process and ex situ as a function of the
temperature in vacuum and in ambient of different gases (H2, N2,
CH4, He). The ns-C films exhibit an ohmic behavior with a room
temperature resistivity in the range of
cm
depending on the growth and storage conditions. Conductivity vs. temperature
measured in vacuum in the range 290–400 K is characterized by activation
energies in the range of 0.3–1.7 eV, the current response does not differ
significantly in gas atmosphere. Nanocomposite carbon-metal films have been
obtained by adding small amounts of metallorganic precursors containing
molybdenum and cobalt during the formation of carbon clusters prior to
deposition. The films are characterized by porous carbon networks containing
small metal and metal carbide clusters. Electrical transport properties of
these films have been studied as a function of temperature, gas pressure and
relative humidity. In particular, the electrical conductivity of the sample
produced with molybdenum showed to be much sensitive to changes in gas
pressure and relative humidity, being characterised by fast and reversible
responses.
PACS: 73.63.-b – Electronic transport in nanoscale materials and structures / 73.23.-b – Electronic transport in mesoscopic systems / 73.61.-r – Electrical properties of specific thin films / 81.40.Rs – Electrical and magnetic properties (related to treatment conditions)
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2003