High-pressure synthesis and structures of lanthanide germanides of LnGe{sub 5} (Ln=Ce, Pr, Nd, and Sm) isotypic with LaGe{sub 5}

Journal Article · Sat Aug 15 04:00:00 EDT 2009 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2009.05.018· OSTI ID:21370515

Fukuoka, Hiroshi ^[1]; Baba, Kazuya; Yoshikawa, Mayumi; Ohtsu, Fumiko; Yamanaka, Shoji ^[1]

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1. Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527 (Japan)

A series of lanthanide penta-germanides LnGe{sub 5} (Ln=Ce, Pr, Nd and Sm) has been prepared by high-pressure (5-13 GPa) and high-temperature (500-1200 deg. C) reaction. CeGe{sub 5} crystallizes in an orthorhombic unit cell (S.G. Immm (71)) with a=4.000(5) A, b=6.192(5) A, c=9.86(1) A, and V=244.1(5) A{sup 3}. The new germanides are isotypic with LaGe{sub 5} consisting of a Ge covalent network with tunnels where guest ions Ln{sup 3+} are situated. The network is composed of sublayers with edge-sharing Ge six-membered rings with only boat conformation. The sublayers are connected by rare eight-coordinated Ge atoms. The cell volume of the compounds systematically decreases from La to Sm compounds, except for CeGe{sub 5,} owing to the lanthanide contraction. The lattice constants of CeGe{sub 5} are smaller than those of the Pr compound because it contains Ce{sup 4+} ions. CeGe{sub 5} is paramagnetic above 2 K, but does not obey the Curie-Weiss law. PrGe{sub 5} and NdGe{sub 5} are Curie-Weiss type paramagnets with Weiss temperatures of -3.3 and -18.4 K. SmGe{sub 5} shows an antiferromagnetic transition at 10.4 K. - Graphical abstract: A series of lanthanide penta-germanides LnGe{sub 5} (Ln=Ce, Pr, Nd and Sm) has been prepared by high-pressure (5-13 GPa) and high-temperature (500-1200 deg. C) reaction.

• OSTI ID: 21370515
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 8 Vol. 182; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANTIFERROMAGNETISM
CERIUM COMPOUNDS
CERIUM IONS
CHARGED PARTICLES
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CURIE-WEISS LAW
GERMANIDES
GERMANIUM COMPOUNDS
IONS
LATTICE PARAMETERS
MAGNETISM
NEODYMIUM COMPOUNDS
ORTHORHOMBIC LATTICES
PARAMAGNETISM
PRASEODYMIUM COMPOUNDS
PRESSURE RANGE
PRESSURE RANGE GIGA PA
RARE EARTH COMPOUNDS
SAMARIUM COMPOUNDS
SYNTHESIS
TEMPERATURE RANGE
TEMPERATURE RANGE 0400-1000 K
TEMPERATURE RANGE 1000-4000 K
TETRAGONAL LATTICES