Influence of the Ln Type and Temperature on the Crystal, Local, and Electronic Structures of Ln Chromates/Chromites | Sciact - CRIS-system of Boreskov Institute of Catalysis

Influence of the Ln Type and Temperature on the Crystal, Local, and Electronic Structures of Ln Chromates/Chromites Full article

Journal

Ceramics International
ISSN: 0272-8842

Output data

Year: 2025, Volume: 51, Number: 7, Pages: 9490-9506 Pages count : 17 DOI: 10.1016/j.ceramint.2024.12.385

Tags

High-entropy oxides (HEOs), Crystal and local structures, Phase transitions, Synchrotron XRD

Authors

Popov V.V. ¹ , Menushenkov A.P. ¹ , Zubavichus Y.V. ² , Yastrebtsev A.A. ¹ , Gaynanov B.R. ¹ , Dubyago F.E. ¹ , Ivanov A.A. ¹ , Rudakov S.G. ¹ , Berdnikova M.M. ¹ , Pisarev A.A. ¹ , Kulikova E.S. ³ , Kolyshkin N.A. ³ , Khramov E.V. ³ , Shchetinin I.V. ⁴ , Novikov S.M. ⁵ , Tatmyshevskiy M.K. ⁵ , Ognevskaya N.V. ⁶ , Tsarenko N.A. ⁶ , Rachenok I.G. ⁶ , Seregina O.N. ⁶

Affiliations

1	National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow, 115409, Russia
2	Synchrotron Radiation Facility SKIF, Boreskov Institute of Catalysis SB RAS, Koltsovo, 630559, Russia
3	National Research Center Kurchatov Institute, Moscow, 123182, Russia
4	National University of Science and Technology MISiS, Moscow, 119049, Russia
5	Moscow Center for Advanced Studies, Moscow, 123592, Russia
6	JSC Design & Survey and Research & Development Institute of Industrial Technology, Moscow, 115409, Russia

The influence of the lanthanide cation type and calcination temperature on the crystal, local, and electronic structures of both individual and high-entropy (HE) Ln chromates/chromites (Ln = La – Yb, and Y) prepared by a coprecipitation is studied by using synchrotron X-ray diffraction, X-ray absorption fine structure spectroscopy, Raman and Fourier transform infrared spectroscopies, scanning electron microscopy with energy-dispersive Xray spectroscopy, simultaneous thermal analysis, and inductively coupled plasma atomic emission spectroscopy. Calcination of X-ray amorphous precursors at 550 ◦C resulted in the formation of individual CrO4 chromates with monoclinic (sp. gr. 21∕ for Ln = La) or tetragonal (sp. gr. 41∕ for Ln = Sm – Yb, Y) structure. The PrCrO4 and NdCrO4 samples were a mixture of monoclinic and tetragonal phases. The HE CrO4 chromates were characterized by tetragonal structure regardless of the 3+ cation type involved. A further increase in temperature ≥ 650 ◦C led to the formation of Ln chromites having the orthorhombic symmetry (sp. gr. for LaCrO3, sp. gr. for individual Ln = Pr – Yb, Y, and HE chromites). For all synthesized CrO3 samples, the lattice parameters, unit cell volumes, Cr–O–Cr bond angles, average Ln-O distances diminish with decreasing the 3+ cation radius. On the contrary, the octahedral distortions within CrO6 units increase with decreasing the 3+ cation radius. An analysis of the electronic structure showed the presence of an oxidation state (3+) for both Ln and Cr cations in all synthesized precursors and Ln chromites, and Cr5+ for Ln chromates. The local environment of the 3+ and Cr3+ cations in HE Ln chromites is close to that of similar ions in individual compounds. The local environment of the La3+ cation in La-containing compounds differs significantly from that of 3+ cations in other Ln chromites (Ln = Nd, Sm, Eu, Gd, Dy, Ho, Yb, Y).

Popov V.V. , Menushenkov A.P. , Zubavichus Y.V. , Yastrebtsev A.A. , Gaynanov B.R. , Dubyago F.E. , Ivanov A.A. , Rudakov S.G. , Berdnikova M.M. , Pisarev A.A. , Kulikova E.S. , Kolyshkin N.A. , Khramov E.V. , Shchetinin I.V. , Novikov S.M. , Tatmyshevskiy M.K. , Ognevskaya N.V. , Tsarenko N.A. , Rachenok I.G. , Seregina O.N.
Influence of the Ln Type and Temperature on the Crystal, Local, and Electronic Structures of Ln Chromates/Chromites
Ceramics International. 2025. V.51. N7. P.9490-9506. DOI: 10.1016/j.ceramint.2024.12.385 WOS Scopus OpenAlex publication_identifier_short.sciact_skif_identifier_type

Submitted:	Oct 8, 2024
Accepted:	Dec 23, 2024
Published online:	Jan 1, 2025
Published print:	Mar 1, 2025

Web of science:	WOS:001437205500001
Scopus:	2-s2.0-85214580699
OpenAlex:	W4405963959
publication_identifier.sciact_skif_identifier_type:	3744

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