ChemInform Abstract: Crystal and Magnetic Properties of U(Mn1‐xFex)2Si2.

Abstract

1991 dielectric properties, magnetic properties dielectric properties, magnetic properties D 9000 -008Crystal and Magnetic Properties of U(Mn1-xFex)2Si2.-Samples of the title solid solution system are prepared in the whole range of composition (x = 0-1) by direct melting of stoichiometric amounts of the powdered and mixed components UMn2Si2 and UFe2Si2. XRD, magnetometric, and Moessbauer measurements show this series to behave similarly to the isostructural ones formed with other elements. All compounds crystallize in the tetragonal ThCr2Si2-type structure (I4/ mmm). Lattice constants a and c obey Vegard's law. The X-ray data are indicative of a small distortion of the tetrahedra, a deviation which is also observed in the Moessbauer spectra. The compositions with x . ltoreq. 0.3 show a ferromagnetic ordering, whereas for the Fe-rich compositions (x ≥ 0.6) the magnetic susceptibility is similar to that of Pauli paramagnets. Curie temp. and hyperfine magnetic field strongly decrease with increasing Fe content. The experimental data are in good agreement with Heisenbergs model in which the magnetic interactions between nearest neighbors and the uniaxial magnetic anisotropy are taken into account. -(BARA, J. J.; HRYNKIEWICZ, H. U.; SZYTULA, A.; J. Less-Common Met. 175 (1991) 2, 259-265; Inst. Phys., Jagellonian Univ., 30-059 Cracow, Pol.; EN) 1