Microwave sintering versus conventional sintering of NiCuZn ferrites. Part II: Microstructure and DC-bias superposition characteristics

• Published in: Journal of magnetism and magnetic materials 2016-06, Vol.407, p.182-187
• Main Authors: Ouyang, Chenxin, Xiao, Shumin, Zhu, Jianhua, Shi, Wei
• Format: Article
• Language: English
• Subjects: DC-bias superposition; Microwave sintering; NiCuZn ferrites
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2016.01.081

NiCuZn ferrites with the composition of (Ni0.48Cu0.10Zn0.42O)1.04(Fe2O3)0.96 were consolidated by microwave sintering (MS) and conventional sintering (CS), respectively. The influences of external microwave field and additives (1wt% BSZ glass or 1wt% Bi2O3) on the microstructure and DC-bias superposition characteristics of NiCuZn ferrites were investigated. Experimental results demonstrated that the final grain size was much larger with higher density since applying microwave field. In addition, for undoped ferrites, coarse grains structure obtained from microwave sintering is harmful to the DC-bias superposition characteristics. However, since adding BSZ glass or Bi2O3, the discrepancy on the final grain size obtained from MS and CS methods is not obvious. NiCuZn ferrites with the addition of BSZ glass or Bi2O3 exhibited a stronger ability to inhibit the drop of permeability under the DC-bias magnetic field. Possible mechanisms behind are discussed in this article. •Magnetization process of NiCuZn ferrite under bias current field is studied.•Coarse grains size from microwave sintering is harmful to endure bias current attack.•BSZ glass and Bi2O3 could enhance the density and DC-bias superposition property.