Cation Distribution and Interatomic Inteactions in Oxides with Heterofalent Isomorphism:I.Stability of the Layered Structure in Rare-Earth Alkaline-Earth Aluminates

摘要

Cation distifution and interatomic distances i trare-earth alkaline-eath aluminates of the K_2NiF_4-and Sr_3Ti_2O_7-type layered structures was studied, The instability of the layered structure in La, Ca-containing compounds was xplained from the rystal-chemical and thermodynamic viewpoints. For LaCaAIO_4, the structure-chemical decomposition mechanism was proposed. The effect of a fourth component on the stability of triple oxides was studied. A stabilizing or destabilizing effect of the deviation frin random distribution of rare-earth and alkaline-earth elements over commo structural positions was demonstrated