Microstructure and magnetic properties of cuaglafe immiscible alloys with an amorphous phase ⁺ 1

The solidification microstructure and magnetic properties of rapidly solidified melt-spun ribbons in Cu _43.2 Ag _32.0 La _4.8 Fe ₂₀ (at%) alloy, which was designed as the combination of the CuAg-based Cu ₅₄ Ag ₄₀ La ₆ alloy with high glass-forming ability and Fe, was investigated. The composite of an amorphous matrix and dispersed crystalline phases were obtained in the melt-spun ribbons. The spherical BCC-Fe nanocrystals, which were surrounded by Cu-rich crystalline phases, were embedded in a CuAgLa-based amorphous matrix. The particular solidification structure in melt-spun ribbons can be explained by liquid-phase separation to form major CuAgLa-rich and minor Fe-rich liquids, an amorphous phase formation in major CuAgLa-rich liquid, and the crystallization of the separated Fe-rich liquid globules during the cooling of the thermal melt. The melt-spun ribbon shows typical ferromagnetic magnetic properties caused by the 10 nm-ordered spherical BCC-Fe nanocrystals.