Phase transformations of the Gd-Fe-Mo ternary compounds with ThMn12-type structure under nitrogen atmosphere

Three single-phase samples of the Gd1.2Fe11-xMox ternary solid solution with the ThMn12-type structure have been exposed to N2 atmosphere and the phase transformations have been studied by X-ray diffraction after annealing at different temperatures. The formation of an interstitial solid solution with nitrogen has been observed below 600 C. At higher temperatures the ThMn12-type phase begins to decompose. The following phase transformations include partial amorphisation and crystallization of α-Fe and a phase of unknown structure type (probable space group P2221, No. 17) with the approximate composition of Fe6Mo7N2. Finally, the ThMn12-type phase disappears and the amorphous phase transforms into GdN. The results of the present study allowed to construct a tentative phase formation diagram for the system Gd1.2Fe11-xMox+N2. (orig.)