Structural and magnetic properties of the intergranular amorphous phase in FeNbB nanocrystalline alloys

摘要

Static and hyperfine magnetic characteristics of an Fes(0.85)Nb(7)B(12.5) nanocrystalline alloy consisting of bcc-Fe nanograins embedded in residual amorphous matrix are compared to those of a hypothetical composite alloy which consists of bulk bcc-Fe and an amorphous alloy in the as-quenched state. The chemical composition of the latter and the proportions of these two constituents were estimated from the mass balance considerations according to the experimentally determined crystalline fraction. The two-phase description of such a hypothetical composite alloy is a posteriori confirmed by the low temperature magnetic characteristics. The degree of compositional heterogeneity of the residual amorphous matrix in the nanocrystalline sample is found to be considerably higher as compared to that of its bulk single-phase as-quenched counterpart. The differences of magnetic behaviour versus temperature allow some aspects of the chemical and structural nature of the intergranular amorphous phase in nanocrystalline alloy to be discussed. [References: 18]