Tailoring magnetic properties of Fe_(0.65)Co_(0.35) nanoparticles by compositing with RE_(2)O_(3) (RE = La, Nd, and Sm)

Abstract

Fe-Co alloys are the most important soft magnetic materials, which are successfully used for a wide range of applications. In this work, the magnetic properties of lanthanide-substituted (Fe_(0.65)Co_(0.35))_(0.95)((RE_(2)O_(3))_(0.05) (RE = La, Nd, and Sm) nanoparticles, prepared by mechanical alloying, are reported. Our comprehensive studies (X-ray diffraction, Mossbauer spectroscopy, scanning electron microscopy with X-ray energy dispersive spectrometry, SQUID magnetometry and differential scannin)g calorimetry) have revealed different properties, depending on the dopant type. The RE_(2)O_(3) addition led to a decrease in the crystallite size and to an increase in the internal microstrain. Moreover, because of the high grain fragmentation tendency of RE_(2)O_(3), the cold welding between Fe-Co ductile particles was minimized, indicating a significant decrease in the average particle size. The parent Fe_(0.65)Co_(0.35) alloy is known for its soft ferromagnetism. For the La-substituted sample, the magnetic energy product was significantly lower (0.450 MG center dot Oe) than for the parent alloy (0.608 MG center dot Oe), and much higher for the Sm-substituted compound (0.710 MG center dot Oe). The processing route presented here, seems to be cost-effective for the large-scale production of soft magnetic materials.