Kim, Sangtae Gwon, Hyo Jin Peek, Sung Wook Kim, Seong Keun Choi, Ji-Won Kim, Jin-Sang Choi, Jung-Hae Kang, Chong-Yun Baek, Seung-Hyub 2024-01-19T21:34:42Z 2024-01-19T21:34:42Z 2021-09-05 2018-09-27 2045-2322 https://pubs.kist.re.kr/handle/201004/120887 Despite the wide applicability of oxynitrides from photocatalysis to refractory coatings, our understanding of the materials has been limited in terms of their thermodynamics. The configurational entropy via randomly mixed O/N or via cation vacancies are known to stabilize oxynitrides, despite the positive formation enthalpies. Here, using tin oxynitrides as a model system, we show by ab initio computations that oxynitrides in seemingly charge-unbalanced composition stabilize by forming pernitrides among metal-(O,N)(6) octahedra. The nitrogen pernitride dimer, =(N-N)=, results in the effective charge of -4, facilitating the formation of nitrogen-rich oxynitrides. We report that the dimer forms only in structures with corner-sharing octahedra, since the N-N bond formation requires sufficient rotational degrees of freedom among the octahedra. X-ray photoemission spectra of the synthesized tin oxynitride films reveal two distinct nitrogen bonding environments, confirming the computation results. This work opens the search space for a novel kind of oxynitrides stabilized by N dimer formation, with specific structural selection rules. English NATURE PUBLISHING GROUP CRYSTAL-STRUCTURE DETERMINATION PLANE-WAVE NITRIDE VISUALIZATION PRINCIPLES PHOSPHORS MELILITE SOLIDS BINARY PHASE A novel class of oxynitrides stabilized by nitrogen dimer formation Article 10.1038/s41598-018-32909-x 1 SCIENTIFIC REPORTS, v.8 SCIENTIFIC REPORTS 8 scie scopus 000445816300007 2-s2.0-85054049773 Multidisciplinary Sciences Science & Technology - Other Topics Article CRYSTAL-STRUCTURE DETERMINATION PLANE-WAVE NITRIDE VISUALIZATION PRINCIPLES PHOSPHORS MELILITE SOLIDS BINARY PHASE