Chemical bonding in EuTGe (T=Ni, Pd, Pt) and physical properties of EuPdGe

Journal Article · Thu Feb 15 00:00:00 EST 2007 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2006.11.013· OSTI ID:21015680

Rocquefelte, Xavier ^[1]; Gautier, Regis ^[1]; Halet, Jean-Francois ^[1]; Muellmann, Ralf ^[2]; Rosenhahn, Carsten ^[2]; Mosel, Bernd D ^[2]; Kotzyba, Gunter ^[3]; Poettgen, Rainer ^[3]

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1. UMR 6226 Sciences Chimiques de Rennes, Universite de Rennes 1-ENSC Rennes-CNRS, Avenue du General Leclerc, F-35042 Rennes Cedex (France)
2. Institut fuer Physikalische Chemie, Universitaet Muenster, Corrensstrasse 30, D-48149 Muenster (Germany)
3. Institut fuer Anorganische und Analytische Chemie, Universitaet Muenster, Corrensstrasse 30, D-48149 Muenster (Germany)

EuPdGe was prepared from the elements by reaction in a sealed tantalum tube in a high-frequency furnace. Magnetic susceptibility measurements show Curie-Weiss behavior above 60 K with an experimental magnetic moment of 8.0(1){mu} {sub B}/Eu indicating divalent europium. At low external fields antiferromagnetic ordering is observed at T {sub N}=8.5(5) K. Magnetization measurements indicate a metamagnetic transition at a critical field of 1.5(2) T and a saturation magnetization of 6.4(1){mu} {sub B}/Eu at 5 K and 5.5 T. EuPdGe is a metallic conductor with a room-temperature value of 5000{+-}500 {mu}{omega} cm for the specific resistivity. {sup 151}Eu Moessbauer spectroscopic experiments show a single europium site with an isomer shift of {delta}=-9.7(1) mm/s at 78 K. At 4.2 K full magnetic hyperfine field splitting with a hyperfine field of B=20.7(5) T is observed. Density functional calculations show the similarity of the electronic structures of EuPdGe and EuPtGe. T-Ge interactions (T=Pd, Pt) exist in both compounds. An ionic formula splitting Eu{sup 2+} T {sup 0}Ge{sup 2-} seems more appropriate than Eu{sup 2+} T {sup 2+}Ge{sup 4-} accounting for the bonding in both compounds. Geometry optimizations of EuTGe (T=Ni, Pt, Pd) show weak energy differences between the two structural types. - Graphical abstract: Cutouts of the [PdGe] and [PtGe] polyanions in the structures of EuPdGe and EuPtGe. Atom designations and some relevant interatomic distances are given.

• OSTI ID: 21015680
• Journal Information: Journal of Solid State Chemistry, Vol. 180, Issue 2; Other Information: DOI: 10.1016/j.jssc.2006.11.013; PII: S0022-4596(06)00603-7; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ACCOUNTING
ANTIFERROMAGNETISM
CHEMICAL BONDS
CRITICAL FIELD
DENSITY FUNCTIONAL METHOD
ELECTRONIC STRUCTURE
EUROPIUM ALLOYS
EUROPIUM COMPOUNDS
EUROPIUM IONS
GERMANIUM ALLOYS
INTERATOMIC DISTANCES
INTERMETALLIC COMPOUNDS
ISOMER SHIFT
MAGNETIC MOMENTS
MAGNETIC SUSCEPTIBILITY
MAGNETIZATION
MOESSBAUER EFFECT
NICKEL ALLOYS
PALLADIUM ALLOYS
PLATINUM ALLOYS
TEMPERATURE RANGE 0065-0273 K
TEMPERATURE RANGE 0273-0400 K