SiO_2凝胶体系中M型锶铁氧体的制备及其磁性能

Preparation and Magnetic Properties of M-Sr Ferrites Embedded in a SiO_2 Matrix

利用溶胶-凝胶法在SiO2凝胶体系中制备了纳米级的锶铁氧体磁性微粒,该磁性微粒组成为30%SrFe12O19和70%SiO2(质量百分含量)。对该微粒进行了XRD分析,利用VSM对样品进行了磁性能研究。研究表明,相对于共沉淀法制备的纯锶铁氧体微粒,在SiO2凝胶体系中制备的SrM微粒仍保持为六方磁铅石型结构,但是粒径明显降低,850℃烧结样品的粒径约为31nm;且内禀矫顽力Hc有了显著的提高,850oC烧结样品的内禀矫顽力达到518.4kA/m,而比饱和磁化强度则有所下降。并对其磁性能变化的原因进行了分析。

M-Sr ferrite powers were prepared using the sol-gel technique in an inert silica xerogel matrix. The mixed samples had a proportion of 30% SrFe12O19 and 70% SiO2 in mass. Samples were analyzed by X-ray diffraction and vibrating sample magnetometry. XRD of the nano-particles shows that the samples are hexagonal in structure, and when thermal treatment temperature is 850 degrees C, particle size of the samples is about 31nm. We have compared the magnetic properties of pure ferrite samples to those embedded in the silica matrix, and it is found that the coercive force H. in ferrite powders embedded in the SiO2 matrix is enhanced, reaching 518.4 Win for the samples prepared with the above metioned powder and sintered at 850 degrees C while its saturation magnetization is decreased.