Electrical and thermal transport properties of the Y_{1 − x}M_xCrO₃system

The effects of substituting divalent metal ions (Mg, Ca, Sr, Ba) for Y in YCrO₃were 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 indicatedp-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.