中文摘要：

采用陶瓷工艺制备了永磁铁氧体Sr0.55-xCaxLa0.45Fe10.85Co0.35O19（0≤x≤0.35）,以X射线衍射仪（XRD）、扫描电子显微镜（SEM）对材料的物相组成和微观形貌进行了表征,以铁氧体永磁测量仪对材料的磁性能进行了检测。结果表明,钙掺杂后磁体主要由M相组成,但钙掺杂量x=0.25时磁体中出现了少量的Fe2O3相。钙掺杂后磁体的晶粒尺寸、长径比增加,当x=0.25时,a向平均晶粒尺寸（平行于试样表面方向）达到1.23μm,长径比达到2.32。随着钙掺杂量增加磁体的剩磁逐渐减小,而钙掺杂量对磁体的矫顽力影响比较复杂,当掺杂量x=0.05、0.35时磁体的矫顽力表现为减小,当掺杂量x=0.15、0.25时磁体的矫顽力明显提高。

英文摘要：

M-type ferrites Sr0.55-xCaxLa0.45Fe10.85Co0.35O19（0≤x≤0.35） were prepared by the conventional ce- ramic method. Phase composition and cross section morphology were characterized by X-ray diffractometer （XRD） and scanning electron microscopy, respectively. Permanent magnetic properties were tested by the hard ferrite magnetic properties measuring instrument. The results showed that the ferrites were all composed of M- type phase after the Ca addition except that the ferrite with x =0.25 was composed of M-type phase and a small amount of ferric iron oxide. The grain size and the aspect ratio of the ferrite increased apparently after the Ca addition. The mean grain size in the ＂a＂ direction was equal to 1.23μm and the aspect ratio was 2.32 when x = 0.25. The remnant magnetism decreases with the increase of the Ca addition amount. While the effect of the Ca addition amounts on the coercive force was complicated. The coercive force was smaller compared to that of the ferrite without the Ca addition when x =0.05, 0.35 and the coercive force was larger when x =0.15, 0.25. The coercive force reached 4.18×10^5A/m when x=0.25.