磁记录材料锶、钡铁氧体的穆斯堡尔研究

A Study of Sr and Ba Ferrite by Moessbauer Spectroscopy

本文用穆斯堡尔效应详细地研究了化学共沉淀法制备的M型锶、钡铁氧体和烧结温度分别为750℃,950℃,1000℃,1100℃,保温2小时急冷的Co0.8Zn1.4W型钡铁氧体,对样品之物相进行了鉴定。计算了晶位分布及掺杂离子的从尤晶位;讨论了烧结温度对材料结构和磁性能的影响以及掺杂对磁性能的影响;探讨了材料宏观磁性与微观磁性之关系。通过计算和与实验对比找到了从穆斯堡尔参数直接计算材料饱和磁化强度的关系式。本文之目的是要弄清烧结温度和掺杂对材料结构和磁性的影响,从而对实际工作提供改进意见。1.

The hexagonal ferrite powders of SrM, BaM, and Co0.6Zn1.4W sintered at different temperatures and prepared by the chemical coprecipitation method were studied by Moessbauer spectroscopy. For SrM and BaM, the parameters of five hyperfine sub-spectra were determined. The Co0.6Zn1.4W was found to be of the M-type rather than W-type from an analysis of its Moessbauer spectra. By calculating the crystal site distribution of ions, it was found that the amount of impurity of Zn and Co increases almost linearly with an increase of the sintering temperature. The Moessbauer spectra revealed that the ions of impurity tend to occupy 12k site rather than 4f1 or 4f2 or 2b site as reported elsewhere. The saturation magnetization is proportional to the total internal sub-magnetic field intensity (Hi).The results obtained are supported by measurement of the saturation magnetization per unit weight and the X-ray diffraction conducted on the samples.