First-principles study on the magnetic properties of ordered   Nd$_{6}$(Fe,Ga)$_{14}$ alloys
  We studied the stable magnetic structure of ordered Nd$_{6}$Fe$_{14-x}$Ga$_x$ ($x = 0, 1)$ alloys, which appears in the grain-boundary (GB) phase of Nd-Fe-B permanent magnets, using first-principles techniques. Slight Ga doping ($x = 1$) was shown to contribute to the stabilization of an anti-ferromagnetic (AF) state, whereas the non-doped case ($x = 0$) was revealed to favor ferromagnetic state rather than AF state with a slight energy difference. 
Kazushige Hyodo, Yuta Toga and Akimasa Sakuma
cond-mat.mtrl-sci