Study on interaction mechanism of different atomic ratio of neodymium, arsenic and iron.

In this study, neodymium and arsenic were sealed into industrial pure iron cylinders at a temperature of 1223 K for 50 h. The interaction mechanism of the Nd-Fe-As system at various atomic ratios was investigated by optical microscopy, X-ray diffractometry, and scanning electron microscopy. Binary compounds FeAs, NdAs, FeAs, and FeNd were the main products formed, with traces of NdFeAs compounds. In addition, at high temperatures, As content affected the diffusion of Fe atoms; the diffusion of Fe increased with an increase in the atomic ratio. Furthermore, the diffusion ability of Nd was weaker than that of As. The major diffusion mechanism of Nd was through the Fe atomic vacancy mechanism. As mainly bind to Fe to form Fe and As compounds. The formation of ternary compounds was confirmed by laboratory experiments and mismatch calculations.