Nb2O5掺杂Co2Z 六角铁氧体的烧结行为和电磁特性

采用固相反应法制备Nb2O5掺杂Co2Z六角铁氧体Ba3(Co0.4Zn0.6)2Fe24O41,Z-型].通过显微结构观察和电磁性能的测试分析,研究了不同Nb2O5掺量对Z-型铁氧体烧结特性和电磁特性的影响.结果表明:由于Nb5 固溶于铁氧体中,增加了空穴浓度,使体扩散加剧,进而促进材料的烧结.适当添加Nb2O5可提高样品的致密化程度,改善Z-型六角铁氧体的显微结构和电磁特性.在Nb2O5掺量为Co2Z一次预烧料质量(下同)的0～0.8%内,随Nb2O5掺量增加,在Z-型六角结构相生长的同时,伴生M-相六角结构.六角结构致密度增加,磁导率增大,铁磁共振频率点移向低频.掺量为0.8%Nb2O5的样品在1 260℃烧结6 h,得到材料的相对密度为95%左右,起始磁导率为33,高μQ积,低损耗角tgδ矫顽力Hcb.

SINTERING BEHAVIORS AND MAGNETIC PROPERTIES OF Co2Z HEXAFERRITES WITH Nb2O5 DOPANT

Z-type hexaferrites Ba3(Co0.4Zn0.6)2Fe24O41] with Nb2O5 dopant were prepared by a solid state method. The influences of different Nb2O5 content on the sintering characteristics and electronic and magnetic properties of Z-type hexaferrite were investigated by examination of the microstructure and by measurement of the magnetic parameters. Experimental results show that the Nb2O5dopant enhances the sintering by increasing bulk diffusion due to the increased vacancy concentration, which is accompanied by the solubility of Nb5+ in the ferrites. The microstructure and magnetic properties of Z-type hexaferrites can be improved and the bulk density can be increased by adding the right amount of Nb2O5. As the amount of Nb2O5 increases, the major phase changes to Zphase; simultaneously, M-phase appears, the bulk density and the initial permeability increase. The mass fraction (the same below) of Nb2O5 added in Z-type hexaferrite is varied from 0 to 0.8 %.However, ferromagnetic resonance peaks moved to the low frequency region. A relative density of 95%, initial permeability of 33, maximumμ Q product, lower tangent of loss angle tg δ and coercive force Hcb were all obtained for the sample with 0.8% Nb2O5 dopant sintered at 1 260 ℃ for 6 h.