The Mössbauer Effect in Eu₃S₄ at Low Temperatures

Y2O3:Eu and the Mössbauer isomer shift coefficient of Eu compounds from ab-initio simulations

“…At the two sites we obtain Δρ 0 = −194.5 Å −3 and Δρ 0 = −0.08 Å −3 respectively. Using the relation IS = αΔρ 0 we derive the respective ISs of −10.5 mm s −1 and 0.0 mm s −1 , in excellent agreement with the experimental estimations [33] of −12.5 mm s −1 and +0.5 mm s −1 . The Eu 2 SiN 3 compound has the Cmce space group with Eu atoms in two inequivalent 8 f positions.…”

Electronic Structure of Strongly Correlated Systems

“…The carrier concentration drops by roughly 3 orders of magnitude in Eu 3 S 4 upon cooling below T co [448]. Eu 3 S 4 has also a phase transition to a ferromagnetic state below T c = 3.8 K [449]. A recent synchrotron X-ray diffraction study for single crystals of Eu 3 S 4 has revealed that a Th 3 P 4 -type I43d structure transforms to a charge-ordered I42d one at T co = 188.5 K [450].…”

“…There is only one type of magnetic Eu 2+ ion in the unit cell of Eu 3 S 4 and two types of nonmagnetic Eu 3+ ions. Eu 2+ has no orbital magnetic moment (Table 11), and Eu 3 S 4 possesses a first-order nonmagnetic phase transition near T co = 188.5 K [447,450], as well as phase transition to a ferromagnetic state below T c = 3.8 K [449]. However, a large difference between T co and T c indicates that the magnetic interactions probably play a minor role for the charge ordering in Eu 3 S 4 .…”

Evidence of a Mixed-Valence State for Europium in the Misfit Layer Compound [(EuS)1.5]1.15NbS2 by Means of a Superspace Structural Determination, Mössbauer Spectroscopy, and Magnetic Measurements

“…At room temperature, the charge #uctuation frequency is fast compared to the MoK ssbauer frequency and only a single line corresponding to Eu> is observed, the splitting Eu>} Eu> occurring at low temperature (20,21) Eu S is known to be a good example of an inhomogeneous mixed-valence state (22). At 6.2 K and below, the MoK ssbauer spectra consist of an hyper"ne Zeeman pattern corresponding to the magnetic ordering of Eu>, and a single line to Eu>, even if this line is partially overlapped by the Zeeman contribution.…”