Structural and magnetic peculiarities of Al sub(86)Ni sub(8)Sm sub(6 ) alloy in amorphous, crystalline, and liquid states

Magnetic, structural, and thermal characteristics of the Al sub(86)Ni sub(8)Sm sub(6 ) alloy in amorphous, crystalline, and liquid states have been studied over a wide temperature range of 4-1900 K. It has been found that the amorphous alloy has a pronounced cluster structure with an average cluster size of 2-3 nm. The crystallization process occurs in four stages and no apparent thermal effect at the glass-transition temperature is observed. The amorphous ribbon has no magnetic order up to 4 K but demonstrates superparamagneic behavior. An analysis of isothermal magnetization curves indicates a possible correlation between structural and magnetically ordered clusters. Anomalous changes in the magnetic susceptibility in the liquid state have been found at temperatures substantially higher than the liquidus temperature; the anomalies indicate structural changes in the melt. The magnetic susceptibility in the amorphous, crystalline, and liquid states was found to be characterized by a high Van Vleck paramagnetic contribution and can be described adequately in terms of the classic Van Vleck theory with allowance for mixed valence effects. The obtained results are interpreted using a concept on the existence of a specific covalent-metallic interaction between aluminum and rare-earth metal atoms.