Li2O-B2O3-SiO2-CaO-Al2O3 and Bi2O3 co-doped gyromagnetic Li0.43Zn0.27Ti0.13Fe2.17O4 ferrite ceramics for LTCC Technology

Abstract A modified low-temperature liquid phase sintering technique was attempted to fabricate Li 0.43 Zn 0.27 Ti 0.13 Fe 2.17 O 4 ferrite ceramics with a compact structure and improved properties through the solid-state reaction route. Fixed amount of Li 2 O-B 2 O 3 -SiO 2 -CaO-Al 2 O 3 (LBSCA) glass was added to Li 0.43 Zn 0.27 Ti 0.13 Fe 2.17 O 4 powders to decrease the sintering temperature below 950 °C, while the addition of Bi 2 O 3 oxide contributed to optimizing the microstructure and improving the magnetic and gyromagnetic properties. Selected parameters including saturation magnetization ( M s ), coercivity ( H c ) and ferromagnetic resonance line width (Δ H ) were investigated as a function of doping content, and their relationships with porosity and microstructure were also discussed. The sample resintered at 940 °C with co-doping of 0.3 wt% of LBSCA glass and 0.03 wt% of Bi 2 O 3 presented excellent magnetic and gyromagnetic properties of M s =73.32 emu/g, H c =120 A/m and Δ H =163 Oe, suggesting that it is promising in the LTCC phase shifter fabrications.