NUKLEONIKA 2007, 52(Supplement 1):S85-S88

PHASE STRUCTURE OF THE NANOCRYSTALLINE Nd2Fe14B/a-Fe MAGNETS WITH DIFFERENT GRAIN SIZE

Izabela Wnuk, Jerzy J. Wysłocki, Anna Przybył

Institute of Physics, Department of Materials Processing Technology and Applied Physics, Częstochowa University of Technology, 19 Armii Krajowej Str., 42-200 Częstochowa, Poland


The effect of the contents of the magnetically hard and magnetically soft phases on the magnetic properties of Nd2Fe14B + a-Fe nanocrystalline magnets, as produced by the method of mechanical alloying, has been established. The phase composition of specimens was determined using X-ray diffractometry and Mössbauer spectroscopy. The Mössbauer examination showed that as the powder milling times increased, the content of the Nd2Fe14B phase increased from 42.8% (after the milling time of 10 h, with a grain size of 44.8 nm) to 66.3% (after the milling time of 48 h, with a grain size of 37.3 nm) and then decreased to 40.3% after 120 h of milling. On the other hand, the content of the magnetically soft phase a-Fe initially decreased (from 27.7%), reaching a minimum after the milling time of 48 h (17.4%) and then increasing to 36.9% after 120 h of milling.