Independence of magnetic behavior for different structural states in melt-spun DyMn6- xGe6-xFexAlx (0 le x le 6)

Structural and magnetic properties of rapidly quenched alloys from the DyMn6−xGe6−xFex Alx (0 x 6) series produced by melt-spinning are investigated by x-ray diffraction (XRD) at room temperature (RT), magnetic measurements in the temperature range from 1.7 to 350 K, and 57Fe Mössbauer spectrometry at 77 and 300 K. Significant similarities in magnetic properties were found between mixed (crystalline and amorphous) DyMn3Ge3Fe3Al3 and fully amorphous DyMn3.5Ge3.5Fe2.5Al2.5 alloys showing essentially the same thermal magnetization behavior with a slight decrease of magnetization. Mössbauer spectra confirm a reduction of magnetic polarization in the transition–metal substructure by the substitution of FeAl by MnGe. The present alloys display complex magnetic behavior which originates from different antiferromagnetically coupled magnetic sublattices (Dyand Fe–Mn sublattice) and the dilution of the Fe sublattice by Mn atoms. In addition, a spin-cluster-glass-like structure is proposed to describe the dynamic effects which occur in the DyMn3Ge3Fe3Al3 alloy, resulting from the competing exchange couplings in this mixed Fe–Mn sublattice.