Formation of bulk ferromagnetic nanostructured Fe40Ni40P14B6 alloys by metastable liquid spinodal decomposition

TL;DR

This study demonstrates the synthesis of nanostructured Fe40Ni40P14B6 alloys via metastable liquid spinodal decomposition, resulting in soft magnetic properties and microstructures with nanoscale grains.

Contribution

It introduces a novel method to produce bulk nanostructured ferromagnetic alloys using liquid spinodal decomposition with controlled undercooling.

Findings

Microstructure changes with undercooling, from intertwining networks to granular morphology.

Average grain sizes are approximately 30 nm and 80 nm.

Samples exhibit soft magnetic behavior with saturation magnetization of about 0.744 T.

Abstract

Nanostructured Fe40Ni40P14B6 alloys ingots of diameter 3~5 mm could be synthesised by a metastable liquid state spinodal decomposition method. The molten Fe40Ni40P14B6 alloy was purified by means of the fluxing technique and thus a large undercooling could be achieved. For undercooling Delta T > 260 K, the microstructure of the undercooled specimen had exhibited liquid state spinodal decomposition in the undercooled liquid state. The microstructure could be described as two intertwining networks with small grains dispersed in them. For undercooling Delta T > 290 K, the overall microstructure of the specimen changed into a granular morphology. The average grain sizes of the small and large grains are ~ 30 nm and ~ 80 nm, respectively. These prepared samples are soft magnets with saturation magnetization Bs ~0.744 T.