Influence of Pr6O11 addition on structural and magnetic properties of mechanically alloyed Fe65Co35 nanoparticles

This work focuses on the synthesize of nanostructured (Fe₆₅Co₃₅)_100-x (Pr₆O₁₁)_x (x = 0, 5) powders using high energy ball milling. The influence of Pr₆O₁₁ on structural, morphological and magnetic properties of Fe₆₅Co₃₅ nanoparticles were carried out by X-ray diffraction (XRD), scanning electron microscopy (SEM) with a dispersive energy analyzer (EDS), vibratory sample magnetometer (VSM) and differential scanning calorimetry (DSC). Results show that the praseodymium oxide addition increased the decrement rate of the crystallite size with milling time of about 27 % and decreased the increment rate of the internal micro-strain of 50 %. Moreover, because of its high grain fragmentation tendency, Pr₆O₁₁ increases the hardness and brittleness of Fe-Co powders. Moreover, it minimized the cold welding between Fe-Co ductile particles leading to a significant decrease in the average particle size (~1µm). The magnetic measurements conducted at room temperature show that the saturation magnetisation (M_s) and the coercivity (H_c) increased with milling time in both compositions. A low M_s and high H_c values were detected in (Fe₆₅Co₃₅)₉₅ (Pr₆O₁₁)₅ nanoparticles. The results demonstrated a soft ferromagnetic nature in all of the synthesized nanoparticles with M_s in the range 207 – 216 emu/g and H_c is found to be 113 Oe.