乙二胺四乙酸含量对M型钡铁氧体薄膜磁性能和微波性能的影响

Influence of EDTA content on the magnetic and microwave properties of M-type barium ferrite thin films

采用有机金属裂解法在Pt/TiO2/SiO2/Si基板上制备M型钡铁氧体(Ba M)薄膜,并着重研究了螯合剂乙二胺四乙酸(EDTA)含量对Ba M薄膜结构、磁性和微波性能的影响。研究发现,当EDTA∶(Ba2++Fe3+)=1(摩尔比)时,Ba M薄膜形成较多的六角形状晶粒,而且磁性能和微波性能较佳,沿c轴生长的取向度高达0.91,饱和磁化强度Ms为302k A/m(μ0Ms=0.38T),在50GHz时铁磁共振线宽ΔH为22k A/m(277Oe)。这是因为适量的EDTA不仅在溶液挥发时能够阻止金属离子的分离和间歇性的沉淀,并且能够促进成形成均匀的前驱液,从而在前驱液分解时能促进形成Ba M,在经过热处理后易形成沿c轴取向、具有六角形状晶粒的Ba M薄膜。

M-type barium ferrite thin films were fabricated on Pt/TiO2/SiO2/Si substrate by metal organic decomposition method, focusing on the effect of elhylene diamine tetraacetic acid on the structure, magnetic and microwave properties of Ba M ferrite thin films. It is found that, when the mole ratio of EDTA∶（Ba^2＋＋Fe^3＋）=1 hexagonal grains are formed, and the Ba M ferrite thin film has excellent magnetic and microwave properties： degree of orientation for c axis of up to 0.91, saturation magnetization Ms of 302 k A/m and the ferromagnetic resonance linewith of 22 k A/m（277Oe） at 50 GHz. These results are due to the fact that appropriate amount of EDTA not only prevents the segregation or intermittent precipitation of metal ions from solution during evaporation but also helps the formation of uniform precursor solution, promoting formation of Ba M during the decomposition of the precursor, which results in c-axis orientation of hexagonal Ba M ferrite thin film after heat treatment.