Matching Permeability and Permittivity of Ga-Substituting Mg-Cd Ferrites for High-Frequency Antennas

• DOI: 10.1007/s10948-019-05228-z
• Publication Date: 2019-08-07T15:06:17Z
• Authors: Pinglu Wang; Meng Zhu; Wanze Zheng; Yang Chen; Fei Xie; Nan Xiao; Bei Hou; Wei Lu; Fuwei Jiang
• Keywords: Dielectric loss; Saturation (graph theory)

This work mainly investigated the effects of gallium-substituting iron on the magnetic and dielectric properties of Mg-Cd ferrites Mg0.8Cd0.2Fe2-xGaxO4 (x = 0.0, 0.05, 0.10, and 0.15) for high-frequency antennas. All the samples were synthesized at 1170 °C. XRD patterns indicated the samples crystallized in normal spinel structure. Magnetic and dielectric spectrum measurement results revealed that the permeability and permittivity of the samples were tailored with change of x value. Finally, the composites possessed excellent matching permeability (μ′) and permittivity (e′) (x = 0.10, μ′/e′ ≈ 1.2), over a long frequency range from 1 to 40 MHz. Comparatively, low dielectric loss tanδe and magnetic loss tanδμ (tanδe ≈ 0.003, tanδμ ≈ 0.035) were obtained due to densification sintering displayed in the SEM figures. Furthermore, magnetic properties were enhanced, such as increased saturation magnetization (approximately 22.14 emu/g) and decreased coercivity (approximately 51.67 Oe), as x value increased. These properties validated the introduction of Ga ions could take effect in high-frequency region applications for Mg-Cd ferrites.