Open AccessEffect of strontium atoms substitution on the features of two-slab structure of Sr1-xCaxLa2Sc2O7 scandates
Author(s) -
Yu. A. Titov,
N. N. Belyavina,
M.S. Slobodyanik,
O. Nakonechna,
N.Yu. Strutynska
Publication year - 2021
Publication title -
french-ukrainian journal of chemistry
Language(s) - English
Resource type - Journals
ISSN - 2312-3222
DOI - 10.17721/fujcv9i1p44-50
Subject(s) - strontium , orthorhombic crystal system , crystal structure , perovskite (structure) , crystallography , substitution (logic) , bond length , rietveld refinement , alkaline earth metal , materials science , crystal chemistry , chemistry , metal , metallurgy , computer science , programming language , organic chemistry
Effects of substitution of the Strontium atoms with smaller Calcium atoms on the structural features of the Ruddlesden-Popper SrLa2Sc2O7 two-slab compound is established. The crystal structure of orthorhombic Sr0.85Ca0.15La2Sc2O7 phase with maximum degree of substitution was determined by the Rietveld method (Fmmm space group, a = 0.5766(2) nm, b = 0.5743(2) nm, c = 2.0522(7) nm). Comparison of the structural features of SrLa2Sc2O7 and Sr0.85Ca0.15La2Sc2O7 shows that such type of substitution leads to a decrease in the (La,Sr)2 - О2 interblock bond length (from 0.222 (2) nm at x = 0 to 0.215 (1) nm at x = 0.15). The decrease in interblock bond length brings the constitution of the two-dimensional structure Sr1-хCaxLa2Sc2O7 closer to the structure of the three-dimensional perovskite, leads to its instability at х > 0.15 and gives a reason to conclude that this factor causes a limitation of region of the Sr1-хCaxLa2Sc2O7 solid solutions with a slab perovskite-like structure. Presence of such structure changes is the precondition for regulation of structural-dependent features of the materials on the base of scandates alkaline-earth and rare earth metals.