Electrical and thermal transport properties of the Y/sub 1-//sub x/M/sub x/CrO3 system

The effects of substituting divalent metal ions (Mg, Ca, Sr, Ba) for Y in YCrO3 were investigated by electrical conductivity, Seebeck coefficient, and thermal conductivity measurements. The electrical conductivity results were consistent with the hopping-type conduction of a temperature-independent concentration of small polarons, with measured activation energies of 0.18--0.26 eV. The Seebeck coefficient increased nearly linearly with temperature and indicated p-type conductivity. Both electrical conductivity and Seebeck coefficient results show a strong dependence on dopant size (ionic radius) and indicate that the highest carrier concentrations were associated with Ca as the dopant, which is attributed to the similar ionic radii of Ca2+ and Y3+. The thermal conductivity decreased slightly with temperature and dopant concentration