Permeability spectra of Co2Z hexaferrite compacts produced via a modified aqueous co-precipitation technique

Low loss and high refractive index in impedance-matched ferrite–silver co-fired ceramics

“…4 shows the refractive index and impedance of the co-fired ceramics. On one hand, all samples have high refractive index of 23.2-26.8, which are much higher than previous reports [6][7][8][9][10][11][12][13][14][15][16][17][18][19]. It indicates that if they are used as the substrate material the physical dimension of HF antennas can be remarkably reduced by a factor of $25.…”

“…High refractive index of substrate materials can reduce the antenna size by a factor of n [2,3], while the impedance matching can alleviate the interface reflectance and reduce the energy trapped in substrate [4]. Great efforts have been paid on singlephased materials [5][6][7][8][9][10][11][12] and composite materials [13] to produce equal permeability and permittivity. For example, Su et al obtained the equal permeability and permittivity of 12 in NiZnCu ferrite [5].…”

Structural and Magnetic Properties of Ba3[Cu0.8−xZnxMn0.2]2Fe24O41 Z‐Type Hexaferrites

“…Lower sintering temperatures of 1150°C-1200°C, however, were sufficient for the production of Z-type hexaferrites using wet chemical methods [13,24,40,41]. e difficulty of obtaining a pure Z-type phase, and its tendency to coexist with other (M-, Y-, and W-type) hexaferrites and spinel phases, has led to adopting different modified synthesis routes, where synthesis of pure Co 2 Z hexaferrite was reported to be achieved at 1250°C sintering temperature [42,43]. Also, it was reported that a Z-type phase can be obtained using two-step solid-state reaction where precursor materials are initially sintered at temperatures between 980 and 1180°C, then ground, and again sintered at about 1230-1300°C [23,44].…”

Dual-ion substitution induced high impedance of Co 2 Z hexaferrites for ultra-high frequency applications

“…One of the effective methods is to increase permeability by fabricating a pure single phase ferrite [6][7][8][9][10]. However, Daigle et al [6] reported that the high frequency permeability of Co 2 Z hexaferrite produced via co-precipitation was significantly enhanced by crystallographically texturing the Co 2 Z ferrites in a rotating magnetic field. In addition, hot-pressing sintered iron-deficient Co 2 Z ferrites resulted in an increased resonant frequency up to 2.5 GHz, while retaining high complex permeability (11-7j) at 2 GHz [10].…”