Ba位和Fe位La-Co共掺杂对BaFe12O19磁性能的影响

通过溶剂热法合成了La-Co共掺杂的Ba_1-xLa_xFe_12-xCo_xO₁₉(x=0、0.1、0.15、0.2和0.25)系列纳米材料样品.X-射线衍射分析结果发现:低掺杂量制备的样品是单相的,但随着La-Co掺杂量的增加,出现了第2相LaFeO₃.用扫描电子显微镜观察了样品的微观形貌,在低掺杂量时,样品呈现明显的片状六角结构,具有较好的分散性.随着掺杂浓度的升高,样品的六角形形貌变得不明显,而且颗粒出现了明显的团聚现象.磁性测量表明:当La-Co掺杂量x=0.1时,矫顽力达到最大值为5 831 Oe,且饱和磁化强度降低缓慢,几乎不变; 随着La-Co掺杂量的进一步增加,饱和磁化强度和矫顽力均出现不同程度的降低,这可能源于La-Co离子掺杂效应和第2相LaFeO₃的出现.研究结果揭示了适量的La-Co掺杂BaFe₁₂O₁₉六角铁氧体在高密度磁存储方面具有潜在的应用前景.

The Effect of Co-Doped La and Co on Magnetic Properties of BaFe12O19 Hexaferrite

The La-Co co-doped Ba_1-xLa_xFe_12-xCo_xO₁₉(x=0、0.10、0.15、0.20 and 0.25)hexaferrites are synthesized by the solvothermal method. X-ray diffraction(XRD)analysis reveals that the samples of low-doped concentration are single-phased.As the La-Co substitution increases,the x≥0.15 samples have LaFeO₃ impurity phase.Scanning electron microscope(SEM)is used to show the morphology and particle size.At low substitution level,the morphology has hexagonal structure in platelet form and good dispersion.With the substitution level increasing,the shape becomes very irregular with aggregates appreciably.The magnetization measurement shows the value of coercivity is as high as 5 831 Oe for x=0.1 sample with only a little decrease in the saturation magnetization.Both saturation magnetization and coercivity drop with increasing La-Co concentration,which can be attributed to the effects of La-Co doping and appearance of LaFeO₃.The results show that La-Co co-doped hexaferrite Ba_1-x·La_xFe_12-xCo_xO₁₉ hexaferrite may be potential candidates for application based on high density perpendicular recording technology.