  Electrically driven thermal changes in PbSc0.5Ta0.5O3 bulk ceramics are
investigated using temperature and electric-field dependent differential
scanning calorimetry and infrared thermometry. On first application and removal
of electric field, we find asymmetries in the magnitude of isothermal entropy
change $\Delta$ S and adiabatic temperature change $\Delta$ T, due to
hysteresis. On subsequent field cycling, we find further asymmetries in the
magnitude of $\Delta$ T due to non-linearity in the isofield legs of
entropy-temperature plots.
