Synthesis of neodymium aluminide by aluminothermic reduction of neodymium oxide

Neodymium aluminide was synthesized from Nd(2)O(3) under vacuum by aluminothermic reduction in an induction furnace. Although the standard free energy change associated with the reduction of Nd(2)O(3) by Al is positive, due to the formation reaction of the intermetallic compound, it was possible to drive the reaction in the forward direction in the presence of excess Al. An attempt was also made to reduce Nd(2)O(3) by Al in the thermit process in the presence of the Fe(2)O(3)-Al thermit mixture so as to make the reaction self-sustaining. A comparison between these two processes was made with respect to the reduction of Nd(2)O(3) by Al. Differential thermal analysis (DTA) was used to study the reaction process. The product was characterized by x-ray diffraction (XRD), x-ray fluorescence (XRF), electron probe microanalysis (EPMA), and optical metallography (OM).