It has been found that the enthalpy of formation of perovskite compounds, ΔfH° (ABO3, B = transition metais), from binary oxides can be well characterized in terms the tolerance factor, t≡(rA+ ro)√2 (rB+ ro), where rA and rB are the radii of A‐site ions with 12‐coordination and B‐site ions with 6‐coordination, respectively, and ΔfH°=−168 + 270(1 − t) kJ·mol−1 for AIBVO3, ΔfH°=−125 + 1000(1 − t) kJ·mol−1 for AIIBIVO3, and ΔfH°=− 90 + 720(1 − t) kJ·mol−1 for AIIIBIIIO3. Although the thermodynamic data of K2NiF4 compounds are not extensive, a similar regularity can be found when use is made of the radii of A‐site ions with 9‐coordination for the K2NiF4 compounds. These correlations will be quite useful in predicting.
|Number of pages||2|
|Journal||Journal of the American Ceramic Society|
|Publication status||Published - 1989 Jan|