STRUCTURAL AND ELECTRICAL-PROPERTIES OF ANTIGRANULOCYTES PALLADIUM CLUSTER FILMS

Thin grandular Pd(x)C1-x films (10 nm < t < 70 nm) have been prepared by codeposition of pure palladium and high purity carbon simultaneously onto NaCl and quartz crystal substrates at room temperature in an ultrahigh vacuum system. By using different evaporation rates for palladium and carbon, we obtained Pd(x)C1-x films with different metal volume fractions x between 0.1 and 1. Structural investigations of the films were carried out by transmission electron microscopy, revealing percolating networks of small palladium clusters embedded in amorphous carbon. The electrical properties were studied by measuring the temperature as well as magnetic field dependence of the film resistant for 1.6 K < T , < 300 K and OT < B < 5T. We find metallic resistance behaviour for films with 0.3 < x < 1 and variable range hopping conductivity for x < 0.3. The low temperature resistance behaviour for films on the metallic side of the metal-insulator-transition (x(c) = 0.3) is analysed in the framework of two- and three-dimensional quantum transport.