EFFECT OF INTERPHASE BOUNDARIES ON RESISTIVITY AND THERMOPOWER OF NANOCRYSTALLINE RE-SI THIN-FILM COMPOSITES

The phase formation, electrical resistivity, and thermoelectric power of the thin film Re-Si composites have been investigated at different stages of the transformation from the amorphous to nanocrystalline sta te. The nanocrystallization was achieved by the annealing of amorphous films with the initial composition Re0.34Si0.66, which is equal to th e composition of the crystalline ReSi2 semiconductor. The composite fi lms include only two phases: the amorphous phase and the nanocrystalli ne ReSi2 with the mean grain size of about 10 nm; however, a large vol ume fraction of the composite films is occupied by interfaces and inte rgrain regions. The transport properties of this semiconductor-semicon ductor system show nonmonotonic dependence on the volume fraction of t he nanocrystalline phase. The role of the interfaces in this peculiar behavior is discussed. [S0163-1829(98)02636-8].