Abstract
In the literature the structure Bi2Sr2CoO6+delta has been described with a variable oxygen nonstoichiometry delta. We identified delta parameter by thermogravimetric measurements and determined thermodynamic properties of Bi2Sr2CoO6+delta.
The heat capacity and enthalpy increments of Bi2Sr2CoO6+delta were measured by the relaxation time method (PPMS) from 2 to 256 K, by differential scanning calorimetry (DSC) from 258 to 355 K and by drop calorimetry from 573 to 1123K. Above-room temperature, the dependence of molar heat capacity under isodynamical (constant po(2)) and conventional isoplethal conditions (constant composition) was derived from the experimental data by the least-squares method.
The low temperature heat capacity was analyzed in terms of a combined Debye-Einstein model. The molar entropy S-m(o)(298.15) = 318.9 J K-1 mol(-1) was evaluated from the low-temperature heat-capacity measurements. (C) 2013 Elsevier Ltd.
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