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Magnetism and 151 Eu Mössbauer Spectra of α‐ and β‐Eu 2 GeS 4
Author(s) -
Tampier Markus,
Johrendt Dirk,
Pöttgen Rainer,
Kotzyba Gunter,
Trill Henning,
Mosel Bernd D.
Publication year - 2002
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/1521-3749(200206)628:6<1243::aid-zaac1243>3.0.co;2-r
Subject(s) - europium , mössbauer spectroscopy , hyperfine structure , magnetism , curie temperature , magnetization , chemistry , magnetic moment , curie , saturation (graph theory) , condensed matter physics , ferromagnetism , materials science , crystallography , nuclear magnetic resonance , magnetic field , physics , atomic physics , ion , quantum mechanics , mathematics , organic chemistry , combinatorics
Single phase α‐Eu 2 GeS 4 was prepared by oxidation of Eu 2 Ge with sulfur. Magnetic susceptibility measurements reveal Curie behavior with an experimental magnetic moment of 7.85(5) μ B /Eu, compatible with divalent europium. Eu 2 GeS 4 orders antiferromagnetically at T N = 5.0(5) K and undergoes a metamagnetic transition at a low critical field of about 0.3(2) T. The saturation magnetization at 2 K and 5.5 T is 6.70(2) μ B /Eu. Despite the two crystallographically different europium sites, 151 Eu Mössbauer spectroscopy experiments show a single signal at 78 K with an isomer shift δ = —12.44(8) mm/s and a line width Gamma = 2.5(1) mm/s indicating purely divalent europium. At 4.2 K weak magnetic hyperfine field splitting is observed. No anomaly was detected in the susceptibility data and the 151 Eu Mössbauer spectra when heating the ferroelectric sample above the Curie temperature of 335 K.