Transport and magnetic properties in the Dy1−xCaxVO3 ceramics

The effect of Ca-doping on the structural, magnetic, electrical, and thermal transport properties has been investigated in Dy1−xCaxVO3 (0 ⩽ x ⩽ 0.2) ceramics. Substituting Ca2+ for Dy3+ leads to a shrinkage of lattice due to the introduction of V4+ with a smaller ionic radius. The parent compound DyVO3 undergoes three spin/orbital ordering (OO/SO) transitions with decreasing temperature at TOO, TSO1 and TSO2, respectively. Increasing the doping level of Ca decreases TSO1, the magnetization above TSO1 and below 50 K, whereas increases TSO2, indicating the Ca-doping has a suppressing effect on the ordering state in DyVO3 system. The thermopower of DyVO3 decreases sharply near TOO while it is not observed in the Ca-doped samples. The result shows that the x = 0.05 Ca-doping is sufficient to melt the OO state in DyVO3 system. Both the thermopower and resistivity decrease significantly with increasing the Ca-doping content. The decreased thermopower is suggested to originate from the combined effect of the increased carrier concentration and decreased spin/orbital degeneracies.

► Combined effect of orbital entropy and carrier concentration on thermopower.
► Ca-doping effect on the ordering states of DyVO3.
► Composition dependent magnetization, resistivity, thermopower and thermal conductivity.