Effect of Pr3+ doping concentration on the structure and magnetic properties of SrFe12O19 compounds

The isotropic Pr-doped SrFe12O19 powders have been synthesized by mechanica l milling and subsequent hear treatment. The effects df Pr3+ doping concent ration and annealing condition on the microstructure and magnetic propertie s have been systematically investigated. It is found that the Pr3+ doping r esults in the increase of the temperature for the formation of hard magneti c compounds. The Curie temperature of PrxSr1-xFe12O19 samples keeps constan t with the variation of composition of the sample;however, it decreases sli ghtly with the increase of annealing temperature. The addition of a small a mount of Pr3+ in the samples is beneficial to the improvement of coercivity , but accompanying with the deterioration of magnetization. The effect of a nnealing temperature on magnetic properties is different for the samples wi th different compositions.