添加Bi_2O_3对水基流延成型制备NiCuZn软磁铁氧体薄磁片磁学性能的影响

Influence of Bi_2O_3 Additive on Magnetic Properties of NiCuZn Ferrite Films Prepared via Aqueous Tape Casting Technology

采用水基流延成型工艺制备Ni0.33Cu0.23Zn0.44BixFe2-xO4（x=0,0.005,0.010,0.015,0.020,0.025,0.030）的铁氧体坯片,研究了不同Bi含量的NiCuZn铁氧体样品在1~200 MHz频率范围内的磁谱和频率在100kHz下磁导率温度系数αμ.结果表明,随着Bi含量的增多,铁氧体样品在13.56 MHz下的磁导率先升后降,截止频率先降后升;在x=0.020时磁导率达到最大值为213.71,截止频率最小;且随着Bi含量增大,磁导率温度系数由正值转为负值,磁导率温度系数绝对值｜αμ｜先减小后增大;当x取值在0.015~0.020之间,在960℃的低温环境下烧结,保温3h即可获得高磁导率和磁导率温度系数较小的NiCuZn铁氧体,可用做近距离无线通讯（NFC）铁氧体隔磁片.

Ferrite films with different Bi contents of Ni0.33Cu0.23Zn0.44BixFe2-xO4（x=0,0.010,0.015,0.020,0.025,0.030）were prepared via aqueous technology of tape casting.The complex permeability spectra with different Bi contents were investigated under1-200 MHz and the temperature coefficient of permeability under 100 kHz was studied.The results revealed that the initial permeability increased firstly and then decreased with the increasing of xunder the frequency of 13.56 MHz,which showed the contrary trend of the cut-off frequency;and the initial permeability reached the maximum value of 213.71,but the cut-off frequency attained the minimum value of 19.47 MHz when xwas 0.020.The coefficient of initial permeability changed from positive to negative,nevertheless,the absolute value ofαμdecreased firstly and then increased.The low permeability temperature-coefficient and high permeability of Ni0.33Cu0.23Zn0.44BixFe2-xO4 ferrite films were obtained with xranging 0.015 to 0.020 and when being sintered at low temperature of 960 ℃for 3h,which turned out to be suitable for the application of near field communication（NFC）.