Influence of Mg substitution on structural, magnetic and dielectric properties of X-type bariumzinc hexaferrites Ba2Zn2-xMgxFe28O46

摘要: Abstract Mg substituted X–type hexagonal ferrites with the chemical composition Ba2Zn2-xMgxFe28O46 (x = 0.0, 0.4, 0.8, 1.2, 1.6 and 2.0) were successfully synthesised by a sol–gel auto–combustion technique, in order to investigate effect of substitution on structural, magnetic dielectric properties. XRD analysis prepared samples revealed formation pure phase. The variations (decreasing trend) lattice parameters indicate incorporation into crystal structure. average crystallite size heated powders was found be range 16–22 nm. For first time, RT hysteresis loops Ba2Zn2Fe28O46 (Zn2X), Ba2Mg2Fe28O46 (Mg2X) measured. saturation magnetisation showed an initial decrease x = 0.4 − then increase x > 1.2, largest final values 63.29 A m2 kg−1 for fully Mg–substituted x = 2.0. value coercivity lies 89.9–209.3 kA m−1 (1130–2630 Oe), results suggest that compositions x = 0.0, 0.4 1.2 possess multi-domain microstructures, while x = 0.8, 2.0 single domain microstructures. room temperature Mӧssbauer spectra analysed six sextets five sublattices, are presented as function substitution. It levels reduce Fe populations at b (spin up) but x > 1.2 these become repopulated fIV down) site, resulting magnetisation. Dielectric such constant loss factor studied frequency, show normal behaviour ferrimagnetic materials. At low frequencies (100 Hz–2 MHz), relative permittivity between 0.3 1.5 above 20 kHz, higher belonging more dense samples. All had lower losses 20 kHz than Zn2X. In complex measurements microwave (500 MHz–13.5 GHz), all real around 7.5, except sample (x = 2.0), which e′ 5.5. two (x = 0.4 1.6) we observed resonances 12.85 13.25 GHz. steady permeability 1.2–1.5 over whole 1–13 GHz range, ferromagnetic resonance (FMR) 1 5 GHz, ∼12.5 GHz.