Synthesis and Thermal Decomposition of High-Entropy Layered Rare Earth Hydroxychlorides

• Published in: Molecules (Basel, Switzerland) Vol. 29; no. 7; p. 1634
• Main Authors: Teplonogova, Maria A, Kozlova, Anfisa A, Yapryntsev, Alexey D, Baranchikov, Alexander E, Ivanov, Vladimir K
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01-04-2024
• Subjects: Crystal structure; Entropy; Instrument industry; layered rare earth hydroxides; microwave-assisted hydrothermal treatment; Neutrons; Solid solutions; unit cell parameters refinement; United States; microwave-assisted hydrothermal treatment; layered rare earth hydroxides; unit cell parameters refinement
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules29071634

The synthesis of multicomponent and high-entropy compounds has become a rapidly developing field in advanced inorganic chemistry, making it possible to combine the properties of multiple elements in a single phase. This paper reports on the synthesis of a series of novel high-entropy layered rare earth hydroxychlorides, namely, (Sm,Eu,Gd,Y,Er)
(OH)
Cl, (Eu,Gd,Tb,Y,Er)
(OH)
Cl, (Eu,Gd,Dy,Y,Er)
(OH)
Cl, and (Eu,Gd,Y,Er,Yb)
(OH)
Cl, using a homogeneous hydrolysis technique under hydrothermal conditions. Elemental mapping proved the even distribution of rare earth elements, while luminescence spectroscopy confirmed efficient energy transfer between europium and other rare earth cations, thus providing additional evidence of the homogeneous distribution of rare earth elements within the crystal lattice. The average rare earth cation radii correlated linearly with the unit cell parameters (0.868 < R
< 0.982) of the high-entropy layered rare earth hydroxychlorides. The thermal stability of the high-entropy layered rare earth hydroxychlorides was similar to that of individual hydroxychlorides and their binary solid solutions.