The absolute thermopower of single phase YBa₂Cu₃O₇ and Y_0.8Er_0.2Ba₂Cu₃O₇ has been measured in the range 250 K to the superconducting transition temperature. It is found that these compounds show a large enhancement of thermopower in the range 150 K down toT_c. This enhancement shows a steep exponential drop as the temperature increases from the transition temperature. The temperature variation of the enhancement is too steep to be accounted for by electron-phonon or electron-local structural excitation mechanisms.

The specific heat of superconducting oxide compound, YBa₂Cu₃O_{7 −x}, is studied using a quasi-adiabatic calorimeter from 4.2 to 60 K. The analysis of the specific heat data below 15 K gives a value of 17 mJ/mole K² for the electronic heat capacity coefficient. The value ofθ_D(0) is determined to be 397±8 K. The variation ofθ_D with temperature was calculated in the temperature range 4.2 to 60 K.

We present DC and low frequency AC magnetization measurements on various RBa₂Cu₃O₇ superconductors. We identify features intrinsic to these compounds, and establish the features originating from intergranular links in sintered pellets. The isothermal magnetization curves, and the temperature dependence of magnetization in field-cooled and zero field-cooled states are shown to be consistent with the calculations done following a recent extension of Bean’s model. Low field anomalies predicted within this model are observed, and yieldH_c1 values of a few Oe. These values are shown to be consistent with the temperature variation of magnetization. A comparison is made with the other existing data and it is demonstrated that earlier quoted values ofH_c1 are gross overestimates.