Title
Magnetodielectric response of composites based on a natural garnet and spinel ferrites for sub-GHz wireless applications
Author
Sibi N, G.Subodh
Year
2021
Abstract
A natural garnet with excellent dielectric properties was mixed with different weight percentages of two spinel ferrites, Ni0.5Zn0.5Fe2O4 (NZO) and LiFe5O8 (LFO) to tailor its magnetodilectric properties. 3 wt% B2O3 was added to enhance the density of the composites. X-ray diffraction study revealed the decomposition of the mineral into hematite and cordierite and vibrational spectroscopic analysis confirmed the non reactivity of decomposed mineral with spinel ferrites. Microstructural analysis shows well densified and almost tightly packed grains for garnet-Ni0.5Zn0.5Fe2O4 (G-N) and garnet-LiFe5O8 (G-L) composites. The optimised dielectric and magnetic properties of 0.5 G-0.5 NZO are εr = 4.1, μr = 1.8, tan δε = 0.02, tan δμ = 0.49, whereas that of 0.5 G–0.5 LFO are εr = 4.4, μr = 1.4, tan δε = 0.001, tan δμ = 0.05 at 1 GHz. Due to the moderate permittivity of garnet a better impedance matching compared to magnetodielectric composites based on high-permittivity dielectric counterparts is observed. Hence, the present study indicates G-N and G-L composites are candidates for sub-gigahertz wireless applications.
Instrument
FTIR-6800
Keywords
garnet, spinel ferrites, magnetodielectric composites, microwave applications