¹⁵⁵Gd Mössbauer Spectroscopy on Intermetallics – An Overview

Abstract

Abstract.155 Gd Mössbauer spectroscopy on intermetallic compounds is a useful complementary spectroscopic tool for the determination of magnetic structures, since the high absorption cross-section strongly hampers neutron diffraction experiments for compounds containing natural gadolinium. The recent trends applied to solid state chemistry and materials sciences for that spectroscopic technique are reviewed. IntroductionThe half-filled 4f shell leads to remarkable magnetic properties for the rare earth metal gadolinium. It has a quite high paramagnetic moment of 7.94 µ B /Gd atom and has been described as a ferromagnet [1]. The complex temperature dependence of its magnetic structure, however, has been controversially discussed since the early description [2]. New investigations on high-purity gadolinium crystals [3] confirm ferromagnetic Our report is written from a synthetic solid state chemist's point of view. We do not go into physical details, but we use the information supplied by the 155 Gd spectra in order to better understand structure-property relationships. Experimental Synthesis techniquesThe various For the detailed synthesis conditions we refer to the original articles. The 155 Gd Mössbauer Spectroscopic SourceGadolinium has several isotopes of which the Mössbauer effect has been observed for 154 Gd,

From 3D to 2D: Structural, Spectroscopic and Theoretical Investigations of the Dimensionality Reduction in the [PtAl2]δ− Polyanions of the Isotypic MPtAl2 Series (M=Ca–Ba, Eu)

“…This parameter was also recently used in order to fit spectra of the solid solution Eu 1− x Sr x PtIn 2 and the 155 Gd Mössbauer spectra of, for example, GdAgGe, GdAuGe, GdAuIn or GdAu 0.44(1) In 1.56(1) , recorded below the magnetic ordering temperature . In all cases the use of θ ( θ =52–61°) is crucial, otherwise values for η outside the defined range are observed …”

“…[94] In all cases the use of q (q = 52-618)i sc rucial, otherwise values for h outside the defined range are observed. [95] 3.5. 27 Al solid-state NMR spectroscopy Figure 7s ummarizes the 27 Al MAS-NMR spectroscopicr esults.…”

Effect of complex magnetic structure on the magnetocaloric and magneto-transport properties in GdCuSi

“…Below 5.1 K, it is ferromagnetic and its magnetic structure changes to antiferromagnetic above 5.1 K and the antiferromagnetic order is retained up to T N = 6.1 K [10, 11]. Magnetic properties and 155 Gd hyperfine interaction parameters for ternary intermetallic GdTX alloys have recently been discussed by Pöttgen et al [12].…”

Magnetic properties of the selected phases from the Eu–Ag–Al and Eu–Ag–Ga systems

“…Such behaviour might be explained by a strong coupling (polarization) of the conduction electrons with the individual europium localized moments and the resulting excess moments can be tentatively ascribed to the contribution coming from d-electrons of Ag. A similar situation takes place for many gadolinium intermetallic compounds [38][39][40][41], where the Gd…”