Low Loss Magneto‐Dielectric Composite Ceramics Ba₃Co₂Fe₂₄O₄₁/SrTiO₃ for High‐Frequency Applications

Abstract

Magneto-dielectric composite ceramics Ba 3 Co 2 Fe 24 O 41 /SrTiO 3 (Co 2 Z/STO) loading with high volume fraction of hexaferrite Co 2 Z (f Co2Z = 60%-95%) are successfully prepared by a hybrid process. The microstructures with homogeneously dispersed constituent grains are observed in these composites. The composites loading with 60%-80% hexaferrite possess stable magneto-dielectric properties in the frequency range from 10 MHz to 1 GHz with both low dielectric loss and magnetic loss. For the composite loading with 60% Co 2 Z, the relative permittivity is 28.08 and permeability is 4.46 (at 10 MHz), the dielectric loss tangent keeps below 0.009 within the frequency range from 10 MHz to 1 GHz. Also, it possesses a magnetic loss tangent of 0.006 and 0.144 at 50 MHz and 1 GHz, respectively, which are much lower than 0.056 and 1.242 of the single Co 2 Z phase at the same frequency. These excellent properties indicate that the low-loss Co 2 Z/STO composite ceramic is a new kind of multifunctional magneto-dielectric material with potential for high-frequency electromagnetic device applications.

Low loss and tailored high‐frequency performances of BaO‐doped NiZnCo magneto‐dielectric ferrites

“…Ferrite ceramics are an important category of magnetic materials that have been extensively used in a large variety of electric and magnetic devices due to their good chemical stability, high resistivity, and excellent magnetic properties . In recent years, with the fast development of electronic and information technologies, the various devices are advancing toward lightweight, miniaturization, and integration, while the magneto‐dielectric properties (note that magneto‐dielectric here refers to the characteristic of having both available permeability and permittivity) of ferrites have aroused increasing attention . In comparison with other classes of ceramic materials, magneto‐dielectric ferrites retain relatively large permeability and permittivity simultaneously over a broad frequency range, providing them unique advantage for realization of high‐performance and miniaturized radio frequency (RF) and microwave devices.…”

“…[1][2][3][4] In recent years, with the fast development of electronic and information technologies, the various devices are advancing toward lightweight, miniaturization, and integration, while the magneto-dielectric properties (note that magneto-dielectric here refers to the characteristic of having both available permeability and permittivity) of ferrites have aroused increasing attention. [5][6][7][8][9][10] In comparison with other classes of ceramic materials, magneto-dielectric ferrites retain relatively large permeability and permittivity simultaneously over a broad frequency range, providing them unique advantage for realization of high-performance and miniaturized radio frequency (RF) and microwave devices. For example in antenna designs, the physical size of a microstrip antenna can be significantly reduced by a miniaturization factor n = (μ′ε′) 1/2 (where μ′ and ε′ are the real parts of permeability and permittivity, respectively) via employing a magneto-dielectric ferrite substrate.…”

The effects of magnetic field and polarization on the permeability and permittivity of (1 –x)Ni0.4Zn0.6Fe2O4+xPb(Zr0.53Ti0.47)O3composites at high frequency

“…The magnetoelectric effect is a second order effect with a low conversion coefficient, which limits its practical application, however, despite much research on both single and composite multiferroic materials. On the other hand, magnetoelectric materials enjoy electric and magnetic properties [3][4][5][6][7] that can be applied at high frequency for multifunction operation [8][9][10][11][12][13]. Thus, it is necessary to investigate the magnetodi electric effect or the interaction between electric and magnetic parts at high or even microwave frequencies.…”