Evidence for the stable existence of the Fe2Nd phase in the Fe-Nd system

We did directional solidification experiments on Fe20Nd80 alloys at several low cooling rates in order to observe the solidification sequence, displayed along the length of the sample. We also took measurements of the transition temperatures around the eutectic temperature using a Calvet type calorimeter. Our results show that the formation of the eutectic L <---->(Nd) + Fe17Nd2 occurs first, and is followed by the eutectic L <---->(Nd) + Fe2Nd. The calorimetric measurements give the temperature of the first eutectic to be 688 degrees C, the temperature of the peritectic formation of the phase Fe2Nd to be 682 degrees C and the temperature of its eutectoid decomposition as 659 degrees C. Thermomagnetic measurements give the Curie temperature of the Fe2Nd phase as 250 degrees C. A new phase diagram for this system is proposed. (C) 1999 American Institute of Physics. [S0021-8979(99)05516-4].