Abstrakt
We synthesized and characterized (Bi0.4Sr0.6)Sr2CoO5-delta using X-ray diffraction (XRD) and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS). In the next step the heat capacity and enthalpy increments of (Bi0.4Sr0.6)Sr2CoO5-delta were measured by physical property measurement system (PPMS), differential scanning calorimetry (DSC) and drop calorimetry.
Oxygen non-stoichiometry was determined using thermogravimetric measurement (TG) and reduction in hydrogen atmosphere. Above room temperature the temperature dependence of the molar heat capacity in the form C-pm = (201.0 + 0.09261 x T - 2184097 x T-2) J K-1 mol(-1) was derived by the least squares method from the experimental data.
The heat capacity was also analyzed in terms of a combined Debye-Einstein model. The molar entropy S-m(o) (298.15) = 219.65 J mol(-1) K-1 was evaluated from the low temperature heat capacity data.