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Abstract An extended series of rare‐earth metal calcium germanides have been synthesized and structurally characterized. The compounds have the general formulaRE5−xCaxGe4(1.5<x<3.6;RE=rare‐earth metal; Ce, Nd, Sm, Tb−Lu) and their structures have been established from single‐crystal X‐ray diffraction methods. They crystallize with the Gd5Si4‐type in the orthorhombic space groupPnma(No. 62;Z=4; Pearson symboloP36), where the germanium atoms are interconnected into two kinds of Ge2‐dimers, formally [Ge2]6−. These studies show that Ca can be successfully incorporated into the hostRE5Ge4structure, whereby trivalent rare‐earth metal atoms can be substituted by divalent calcium atoms. Rare‐earth metal and calcium atoms are arranged in distorted trigonal prisms and cubes, centered by either Ge or Ca atoms. On one of the metal sites, the substitution is preferential and in 9 out of the 10 refined structures, the Wyckoff site 4cis found almost exclusively occupied by Ca. On the other two metal sites the substitution patterns appear to be governed by the mismatch between the size of theRE3+and Ca2+ions. This work further demonstrates the ability for the Gd5Si4structure type to accommodate the substitution of a non‐magnetic element while maintaining the global structural integrity.
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Flux crystal growth of a series of calcium rare earth silicate chlorides CaLnSiO4Cl (Ln = Pr, Nd, Sm, Eu, Gd, and Tb): Mixed anion materials with a spodiosite-type structure
Not AvailableA series of calcium rare earth silicate chlorides, CaLnSiO4Cl (Ln = Pr, Nd, Sm, Eu, Gd, and Tb), was obtained as single crystals from flux crystal growth. The structures were determined by single crystal X-ray diffraction and were found to be related to the spodiosite /Wagnerite mineral structure, Ca2PO4F. The obtained compositions are variations of the spodiosite structure that result from two simultaneous elemental substitutions. Replacing one calcium for one rare earth element and the simultaneous replacement of one VO43- or PO43- with one SiO44-. CaEuSiO4Cl was found to luminesce, and its photoluminescence spectrum is reported.
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- Award ID(s):
- 2401995
- PAR ID:
- 10658985
- Publisher / Repository:
- Elsevier
- Date Published:
- Journal Name:
- Solid State Sciences
- Volume:
- 170
- Issue:
- C
- ISSN:
- 1293-2558
- Page Range / eLocation ID:
- 108105
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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