A Study Of Structure And Magnetic Properties Of RFe_12-xM_x Rare Earth Compounds

PrFe12-xSix(x=0.70,0.90,1.10,1.30) and PrFe12-xNbx(x=0.65,0.70,0.75,0.80) compounds we are prepared by means of arc smelting and high temperature quenching. The X-ray diffraction has been used to analysis the lattice structure of the various compounds, and to use X’Pert Plus software to make X-ray diffraction peak data of free powder samples and oriented samples to fit on each sample to determine the lattice constant and magnetic anisotropy. With the help of differential scanning calorimetory and vibrating sample magnetometer, the author measured and determined the Curie temperature of each sample and analyze the cause and mechanism of the related phenomenon. The hysteresis loop of each sample of PrFe12-xSix series has been measured using a vibrating sample magnetometer, and then the author calculated the coercivity of each sample and analyzed the rules and reason for specific changes.For the PrFe12-xSix(x=0.70,0.90,1.10,1.30)and PrFe12-xNbx(x=0.65,0.70,0.75,0.80) two series of compounds, the XRD shows that their lattice structure are1:12-type tetragonal ThMn12structure with I4/mmm space group. Each sample has a small amount of a-Fe phase as impurity. For the PrFe12-xSix (x=0.70,0.90,1.10,1.30) compounds, the lattice parameters a, b and V decrease monotonically with increasing Si content, and minor FeSi phase in it. The Curie temperature Tc intends to increasing Si content; For the PrFe12-xNbx compounds, the lattice parameters a, b and V increase monotonically with increasing Nb content, and a small amount of Fe2Nb phase in it. The Curie temperature Tc intends to decreasing Nb content.