Magnetic properties of hexagonal Laves-phase Zr(Cr1-xFex)2 compounds

Zr(Cr1-xFex)2 samples with the C14 structure were prepared in an arc furnace for x=0.2-0.85. Magnetization, ac susceptibility and Moessbauer spectra were measured in the 4.2-300 K temperature interval. Saturation magnetic moments were obtained from magnetization data and iron moments were obtained from Moessbauer spectra; the Cr moment was found to be negligible. A new environment-dependent model for the formation of Fe moments was proposed. Arrott plots showed that long-range magnetic order only occurs for x>0.7. Spin glass properties were studied in detail for x≤0.7. Samples with x=0.8-0.85 were ferromagnetic with a re entrant spin glass transition. A magnetic-phase diagram was drawn for this system. (author)