AUTHOR=Abarca Morales Edgar 

TITLE=The 4-Octahedra model

JOURNAL=Frontiers in Materials

VOLUME=11

YEAR=2024

URL=https://www.frontiersin.org/journals/materials/articles/10.3389/fmats.2024.1461579

DOI=10.3389/fmats.2024.1461579

ISSN=2296-8016

ABSTRACT=<p>This work comprises a generalization of a simple geometric model originally developed to describe coupled rotations of corner-sharing octahedra in the surface layer of <inline-formula id="inf1"><mml:math id="m1" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow><mml:mi mathvariant="normal">S</mml:mi><mml:mi mathvariant="normal">r</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:math></inline-formula>RuO<sub>4</sub> under uniaxial compression. The main objective of the model is to establish a link between the experimental global strain configuration and the possible microscopic mechanisms and compatible geometries by which the octahedra accommodate the applied strain. In achieving this, a useful and intuitive parametrization of four-site two-dimensional systems of corner-sharing octahedra has been established, which can be readily extended to three dimensions and <inline-formula id="inf2"><mml:math id="m2" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>N</mml:mi><mml:mo>&gt;</mml:mo><mml:mn>4</mml:mn></mml:math></inline-formula> inequivalent sites or directly employed to analyze the octahedral configuration of many perovskites, transition metal oxides (TMOs), and layered compounds.</p>