Effect of NiZn Ferrite Nanoparticles upon the Structure and Magnetic and Gyromagnetic Properties of Low-Temperature Processed LiZnTi Ferrites

Abstract

NiZn ferrite nanoparticles (2−20 wt %) of composition Ni 0.4 Zn 0.6 Fe 2 O 4 were introduced into LiZnTi ferrite of composition Li 0.42 Zn 0.27 Ti 0.11 Fe 2.2 O 4 and sintered at a temperature of 920°C for 2 h, well below that of the Ag melting point. Here, LiZnTi ferrites were prepared by a solidstate reaction method, and NiZn ferrite nanoparticles were fabricated by a hydrothermal chemical technique at 180°C. A low ferromagnetic resonance (FMR) line width, low coercivity, and high magnetic moment were achieved after refinement of the heat treatment conditions of the mixture. Riveted full profile refinement of the X-ray powder diffraction patterns and analysis of Mossbauer spectra were employed to study the structure and caption distribution. The results confirm a pure spinel phase after processing. A narrow FMR line width of 152.5 Oe, a reduced coercivity of 132.9 A/m, and an improved saturation magnetization of 74.23 emu/g were obtained by way of the addition of 8 wt % NiZn ferrite nanoparticles.

Li2O-B2O3-SiO2-CaO-Al2O3 and Bi2O3 co-doped gyromagnetic Li0.43Zn0.27Ti0.13Fe2.17O4 ferrite ceramics for LTCC Technology

“…In this work, the effect of porosity on coercivity is lower than the grain size. composite samples resintered in air at 940°C for 5 h. All the experimental data were fitted better with a Lorentzian than Gaussian distribution, indicating relatively low FMR line width (ΔH) [12,36].…”

“…As integral microwave components, phase shifters have been demonstrated miniaturization using LTCC ferrite tapes [1][2][3][4][5]. One member of gyromagnetic materials, LiZnTi ferrites have been investigated and applied in phase shifters due to their high Curie temperature, excellent temperature stability, high remanence square ratio, wide range of saturation magnetization, and low cost [6][7][8][9][10][11][12][13][14]. However, these ferrites prepared by traditional methods need to be sintered above 1100°C to achieve high densification and uniform grain size distribution.…”

“…However, abnormal grain growth (AGG) occurs in lowtemperature liquid-phase sintered Li-based ferrites or other ceramics while their porosity generally remains above 2%, which would deteriorate their performances such as magnetic loss for microwave ferrite ceramics [8,[13][14][15][19][20][21][22]. In our prior work, NiZn ferrite nanoparticles were adopted to introduce into LiZnTi ferrites to suppress AGG of the microsize grains; nevertheless, the porosity was still larger than 2% [12]. In this work, we chose Li 2 O-B 2 O 3 -SiO 2 -CaO-Al 2 O 3 (LBSCA, molar ratio of 52.45:31.06:11.99:2:2.5) glass and Bi 2 O 3 oxide to co-dope Li 0.43 Zn 0.27 Ti 0.13 Fe 2.17 O 4 ferrite ceramics using the solid-state method with a resintering condition (annealing), seeking to suppress AGG and obtain dense structure, which is conducive to improving the gyromagnetic properties.…”

Dielectric properties of Li doped Ni-Zn ferrite

“…where C is the capacitance of the sample, t is the thickness; A is the surface area, and ε o is the permittivity of free space (ε o = 8.85×10 −12 F/m). From dielectric constant and dissipation factor (D f ), the ac conductivity (σ ac ), of the ferrite samples can be calculated using the relation [12]:…”

Investigation of grain boundary diffusion and grain growth of lithium zinc ferrites with low activation energy

“…In recent years, lithium-zinc ferrite ceramics have attracted more interest for use in X band and millimeter wave (MMW) phase shifters because of their high saturation magnetization (4pM s ), high Curie temperature (T c ), and low ferromagnetic resonance linewidth (DH). [11][12][13][14] Similarly, when the sintering temperature was decreased tõ 900°C, insufficient grain growth of the ferrite ceramics resulted in deterioration of magnetic performances, especially for the ferromagnetic resonance linewidth (DH). 15,16 To reduce the value of DH for ferrite ceramics sintered at low temperature, methods in which low-melting point oxides or glasses are selected as sintering additives have been widely reported.…”