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 00:00:00 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, Vol. 182, Issue 8; Other Information: DOI: 10.1016/j.jssc.2009.05.018; PII: S0022-4596(09)00226-6; Copyright (c) 2009 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

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