Thermal conductivity of amorphous carbon thin films

Thermal conductivities Lambda of amorphous carbon thin films are measured i n the temperatures range 80-400 K using the 3 omega method. Sample films ra nge from soft a-C:H prepared by remote-plasma deposition (Lambda = 0.20 W m (-1) K-1 at room temperature) to amorphous diamond with a large fraction of sp(3) bonded carbon deposited from a filtered-are source (Lambda = 2.2 W m (-1) K-1). Effective-medium theory provides a phenomenological description of the variation of conductivity with mass density. The thermal conductivit ies are in good agreement with the minimum thermal conductivity calculated from the measured atomic density and longitudinal speed of sound. (C) 2000 American Institute of Physics. [S0021-8979(00)07221-2].