Relation between the Co-O bond lengths and the spin state of Co in layered Cobaltates: a high-pressure study

Autor: Yi-Ying Chin, Hong-Ji Lin, Zhiwei Hu, Chang-Yang Kuo, Daria Mikhailova, Jenn-Min Lee, Shu-Chih Haw, Shin-An Chen, Walter Schnelle, Hirofumi Ishii, Nozomu Hiraoka, Yen-Fa Liao, Ku-Ding Tsuei, Arata Tanaka, Liu Hao Tjeng, Chien-Te Chen, Jin-Ming Chen
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: Scientific Reports, Vol 7, Iss 1, Pp 1-9 (2017)
Druh dokumentu: article
ISSN: 2045-2322
DOI: 10.1038/s41598-017-03950-z
Popis: Abstract The pressure-response of the Co-O bond lengths and the spin state of Co ions in a hybrid 3d-5d solid-state oxide Sr2Co0.5Ir0.5O4 with a layered K2NiF4-type structure was studied by using hard X-ray absorption and emission spectroscopies. The Co-K and the Ir-L 3 X-ray absorption spectra demonstrate that the Ir5+ and the Co3+ valence states at ambient conditions are not affected by pressure. The Co Kβ emission spectra, on the other hand, revealed a gradual spin state transition of Co3+ ions from a high-spin (S = 2) state at ambient pressure to a complete low-spin state (S = 0) at 40 GPa without crossing the intermediate spin state (S = 1). This can be well understood from our calculated phase diagram in which we consider the energies of the low spin, intermediate spin and high spin states of Co3+ ions as a function of the anisotropic distortion of the octahedral local coordination in the layered oxide. We infer that a short in-plane Co-O bond length (
Databáze: Directory of Open Access Journals
Nepřihlášeným uživatelům se plný text nezobrazuje