CONDUCTION MECHANISMS DEDUCED FROM THERMOELECTRIC-POWER AND DIRECT-CURRENT CONDUCTIVITY MEASUREMENTS IN COEVAPORATED MN SIOX THIN-FILMS/

The thermoelectric power and direct-current (d.c.) conductivity of co- evaporated Mn/SiOx films deposited at the rate of 0.5 nm s(-1), 100 nm thick and containing 1, 3 and 5 at% Mn have been measured over the te mperature ranges 258-588 K and 110-575 K, respectively. Thermoelectric power and d. c. conductivity measurements suggest that, over the temp erature range 258-360 K, conduction occurs by hopping due to delocaliz ed electrons at the Fermi level and electrons in donor localized state s, intrinsic over the temperature range 360-558 K and metallic like ab ove 558 K. The d.c. conductivity is activated over the whole temperatu re range investigated.