Effect of iron deficiency on microstructure and magnetic properties of high dielectric constant YIG

With the rapid advancement of communication technologies toward higher frequencies and miniaturization, microwave devices are imposing increasingly stringent performance requirements on fundamental magnetic materials. Optimizing the saturation magnetization and dielectric constant of ferrite materials can enhance the transmission efficiency and frequency response of microwave devices, thereby meeting the evolving technical requirements. In this study, we synthesized a series of yttrium iron garnet ferrites with the chemical composition Bi 1.4 Ca 0.3 Y 1.3 Zr 0.15 Sn 0.15 In 0.2 Fe 4.5-x O 12-1.5x (0 ≤ x ≤ 0.3) using the conventional solid-state reaction method. The effects of iron deficiency on the structure and electromagnetic properties of these ferrites were systematically investigated. The results demonstrate that controlled iron deficiency effectively enhances saturation magnetization (4πMs) while reducing dielectric loss (tanδ), without altering the garnet phase structure or dielectric constant (ε'). However, excessive iron deficiency induces the formation of a secondary YFeO 3 phase, severely degrading material properties. The sample with x = 0.2 exhibits outstanding comprehensive performance, with a high saturation magnetization (1903 Gs), an elevated dielectric constant (25.2), and a low dielectric loss (4.67 × 10 -3 ). These high-performance ferrite materials show great potential for applications in next-generation microwave devices.