Magnetic properties and 155Gd Moessbauer spectroscopy of the icosahedral quasicrystal Ag50In36Gd14

The results of x-ray diffraction, magnetic susceptibility, and 155Gd Moessbauer spectroscopy studies of the recently discovered icosahedral quasicrystal Ag50In36Gd14 are reported. The studied quasicrystal has a simple six-dimensional Bravais lattice with the six-dimensional hypercubic lattice constant of 7.805(2) A. The observed broadening of the diffraction Bragg peaks reflects the presence of the topological/chemical disorder. The temperature dependence of the magnetic susceptibility follows the Curie-Weiss law with an effective magnetic moment of 8.15(1) μB per Gd atom and the paramagnetic Curie temperature of -37.1(2) K. The studied quasicrystal is a spin glass with a freezing temperature of 4.25(5) K. The presence of a distribution of the electric quadrupole splitting in the Moessbauer spectra indicates the existence of a multiplicity of Gd sites. The values of the principal component of the electric field gradient tensor and the asymmetry parameter at these sites are, respectively, -4.91(10) x 1021 V cm-2 and η = 1.00(20). The Debye temperature of Ag50In36Gd14 is 199(2) K. The hyperfine magnetic field sets in at a temperature higher than the freezing temperature