Results for “Y(BO2)3”

DOE OSTI2020

Materials Data on Y(BO2)3 by Materials Project

Y(BO2)3 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Y3+ is bonded in a 2-coordinate geometry to ten O2- atoms. There are a spread of Y–O bond distances ranging from 2.29–2.76 Å. There are two inequivalent B3+ sites. In the first B3+ site, B3+ is bonded in a tetrahedral geometry to four O2- atoms. There is two shorter (1.46 Å) and two longer (1.49 Å) B–O bond length. In the second B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of B–O bond distances ranging from 1.34–1.42 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Y3+ and two B3+ atoms. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Y3+ and two B3+ atoms. In the third O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Y3+ and one B3+ atom.

36 MATERIALS SCIENCE↗

DOE OSTI2024

Surface reconstructions and electronic structure of metallic delafossite thin films

The growing interest in the growth and study of thin films of low-dimensional metallic delafossites, with the general formula ABO2, is driven by their potential to exhibit electronic and magnetic characteristics that are not accessible in bulk systems. The layered structure of these compounds introduces unique surface states as well as electronic and structural reconstructions, making the investigation of their surface behavior pivotal to understanding their intrinsic electronic structure. In this work, we study the surface phenomena of epitaxially grown PtCoO2, PdCoO2, and PdCrO2 films, utilizing a combination of molecular-beam epitaxy and angle-resolved photoemission spectroscopy. Through precise control of surface termination and treatment, we discover a pronounced 3×3 surface reconstruction in PtCoO2 films and PdCoO2 films, alongside a 2 × 2 surface reconstruction observed in PdCrO2 films. These reconstructions have not been reported in prior studies of delafossites. Furthermore, our computational investigations demonstrate the BO2 surface’s relative stability compared to the A-terminated surface and the significant reduction in surface energy facilitated by the reconstruction of the A-terminated surface. These experimental and theoretical insights illuminate the complex surface dynamics in metallic delafossites, paving the way for future explorations of their distinctive properties in low-dimensional studies.

Materials Science↗