Anisotropy and magnetic ordering in the new phase Nd₃(FeTi)₂₉

Recently, a new rare-earth iron-rich phase 3:29 has been found to be stabilized using Ti. The Curie temperature T_C=413 K is considerably higher than in the related Nd₂Fe₁₇ compound. The easy magnetization direction lies in the basal plane of the monoclinic structure at room temperature. A magnetic anomaly has been detected at T_SR=233 R in the thermal dependence of the AC initial susceptibility, which has been related to a spin reorientation transition from an easy-plane phase towards an easy cone at low temperatures. Thermal expansion measurements clearly show an extra magnetic contribution at T_C, a weak anomaly being also perceptible at T_SR. The anisotropy field measurements using the SPD technique have confirmed the existence of these two magnetic phases.