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A value for the nuclear magnetic moment of theI=2 (80.56 keV) level of166Er has been obtained by comparing measurements made by the Mössbauer effect on166Er with NMR measurements on the ground state of167Er in the same matrix. From measurements on ErFe2, ErAl2 and ErZn we obtain the value µN (166Er; 80.56 keV)=0.650±0.010 n.m. This result is slightly higher than previously proposed values.

Abstract: The magnetic and quadrupole hyperfine interactions in amorphous EuFe2Si2 have been measured using57Fe and151Eu Mssbauer spectroscopy. The distributions in the various parameters have been found using the Fourier coefficient method. Novel features of the results are that the Eu charge state (4f occupation number) changes between the crystalline and amorphous phases and that whereas in the crystalline phase neither Eu nor Fe is magnetic, both become so in the amorphous phase.

Mössbauer measurements on the diluted crystals FexMg1−xCl2 show that fluctuating magnetic clusters are present. These can be related to the known spin-glass properties of these compounds. The fluctuating frequencies depend on temperature and the fluctuations can be suppressed by a sufficiently high external magnetic field

Abstract: From Mssbauer and resistivity measurements on (La2−y Sr y ) CuO4−δ samples doped with 5/100057Fe, three successive phases are observed depending on they value: a semiconducting antiferromagnetic phase fory<0.02; a semiconducting phase with two-dimensional spin-glass Cu magnetic order for 0.020.07. The Mssbauer data show that a Cu spin-glass order survives in the superconducting phase up toy∼0.15. Fory>0.15, a different type of magnetic ordering is observed on57Fe, which is clearly governed by the iron impurities interacting through the Cu sublattice.