Study on microwave properties of low temperature fired NiZnCu gyromagnetic ferrite

This paper describes the microwave properties of low temperature fired Ni0.6CuxZn(0.4-x)Fe1.96+delta O4 gyromagnetic ferrite material synthesized by conventional oxide process with Bi2O3 additives. It is found that 60-63 mol % Ni and 5 mol % Cu contents have the advantage to keep the material with both low-fired characteristic and high saturated magnetization with 3 wt % Bi2O3 additives. Considering the conditions of milling, calcination, and sintering process, the low temperature fired NiCuZn gyromagnetic material was prepared with excellent microwave performances. The saturated magnetization M-s of the sample is 337 kA/m, the ferromagnetic resonance linewidth Delta H and dielectric loss tg delta(epsilon) less than 16 kA/m and 5.7 X 10(-4), respectively, which has the potential applications for low temperature cofired ceramics technology to develop microwave chip circulator/isolator and passive integrated substrate. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3061950]