Electrical resistivity of iron silicide-barium boromolybdate glass composites

Composite materials prepared from barium boromolybdate glasses (MoO3 conten t of 8, 12, or 16 wt %) and a cermet containing iron silicides were charact erized by x-ray diffraction and resistivity measurements as a function of t emperature. Increasing the content of the semicrystalline constituent first reduces the resistivity and then increases it to its original level. The m inimum resistivity of the materials corresponds to a positive temperature c oefficient of resistance. The results are interpreted in terms of the micro - and electric structures of the composites.