稀土元素La掺杂BaFe_(12)O_(19)微结构和磁性能的研究

Study on the structural and magnetic properties of La-doped barium ferrites

用固相法制备了镧掺杂M型钡铁氧体(Ba1-xLaxFe12O19,x=0.0—0.6),针对不同取代量与不同温度的烧结,研究取代量和温度对钡铁氧体微结构和磁性能的影响.在烧结温度为1100—1175C,当x=0.0—0.6时,样品主要有单一的六角M型钡铁氧体相构成.SEM表明,La离子的加入不会影响钡铁氧体微观形貌.在磁性能方面,随着La离子的增加,钡铁氧体的饱和磁化强度先增加后减小,矫顽力逐渐增加.在同一取代量下,钡铁氧体的饱和磁化强度随烧结温度升高呈现上升趋势,矫顽力随着烧结温度的升高而降低.饱和磁化强度在x=0.2,烧结温度1175℃时达到最大值62.8emu/g,矫顽力在x=0.6,烧结温度1125℃时达到最大值3911.5Oe.

Magnetic properties of La doped M-type barium ferrites are studied. The samples are prepared by the standard solid state reaction method. The influences of La3＋ on structures and magnetic properties of barium ferrites （Ba1-xLaxFe12019） are investigated. Single- phase M-type barium ferrites with chemical composition of Ba1-xLaxFe12O19 （x = 0.0~0.6） are formed by sintering at 1100- 1175 ℃ in air. Scanning electron microscopy （SEM） reveals that the La doping has no effect on the structure of barium ferrite. Vibrating sample magnetometer （VSM） shows that with the valaue of x increasing, the saturation magnetization （Ms） increases, reaching a maximum at x = 0.2 and then decreases and the coercivity of the sample increases continuously. The value of Ms reaches a maximum value of 62.8 emu/g at x = 0.2 and 1175 ℃, and the He reaches a maximum value of 3911.5 Oe at x = 0.6 and 1125℃.