Low temperature co-fired Sn-Ca co-substituted Y3Fe5−2xSnxCaxO12 ferrites for microwave devices application

Abstract

To meet the requirements of improving performances and realizing miniaturization and integration for microwave devices, low temperature co-fired ceramic (LTCC) technology emerged and has been widely investigated. In present work, with 2.5wt% BBSZ additive, low temperature co-fired Sn4+ and Ca2+ ions co-doped Y3Fe5−2xSnxCaxO12 (x=0.0∼0.8 with 0.2 step) ferrite materials were synthesized using solid state reaction process. The structural characterizations such as X-ray diffraction, scanning electron microscope and bulk density have been carried out. Single phase YIG can be obtained with 2.5wt% BBSZ sintered at 1050 °C. The bulk density of samples decreased with Sn-Ca substitution increasing. The room temperature hysteresis loops, dielectric loss and FMR linewidth were measured. Saturation magnetization (Ms) and coercivity (Hc) extracted from the loops. With substitute content increasing, the saturation magnetization decreased (from 50.25 emu/g to 31.96 emu/g) due to weak magnetism of Sn-Ca. Coercivity decreased first from 40.14 Oe to 24.14 Oe, and then increased to 25.34 Oe. When x=0.4, the minimum FMR linewidth value was 31 Oe. Meanwhile, the value of tanδε was about 0.033∼0.047 at high frequency (10 MHz∼100 MHz). These garnets have excellent magnetic properties and low dielectric loss which made a promising material for microwave devices can be used.