Directly quenched nanocrystalline (Pr,Dy)–(Fe,Co)–Zr–Ti–B magnets

Studies of rapidly solidified Pr9−xDyxFe60Co13Zr1+yTi3−yB14 (where x = 0, 1 and y = 0, 1) thick ribbons, 1 mm diameter (dia.) rods and 3 mm outer diameter (o.d.) tubes show good hard magnetic properties in as-cast state. Change of Ti to Zr ratio results in variation of the glass forming abilities that has significant impact on magnetic properties. Low temperature annealing at 573 K/10 min of the Pr9Fe60Co13Zr1Ti3B14 alloy samples resulted in an improvement of their coercivity field. The X-ray diffractometry and Mössbauer spectroscopy allowed determining the volume fractions of constituent phases formed during rapid quenching.

► Pr9−xDyxFe60Co13Zr1+yTi3−yB14 (x = 0, 1 and y = 0, 1) alloys shown changes of magnetic properties with the shape of rapidly solidified samples.
► Two crystalline phases precipitate during rapid solidification: the hard magnetic Pr2(Fe,Co)14B and paramagnetic Pr1+ɛFe4B4 and majority amorphous.
► The best magnetic properties in group of ribbons containing 2 at.% of Zr.
► Better glass forming abilities of 1 at.% of Zr alloys thus improvement of magnetic properties of bulk samples.
► Dy admixture improves the coercivity field.