Mohapatra, PP and Pittal, S and Dobbidi, P (2020) Temperature dependent broadband dielectric, magnetic and electrical studies on Li1-xMg2xFe5-xO8for microwave devices. In: Journal of Materials Research and Technology, 9 (3). pp. 2992-3004.
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Abstract
Polycrystalline samples of Mg substituted lithium ferrites (Li1-xMg2xFe5-xO8(LMFO) (x = 0,0.003, 0.005, 0.007 and 0.01) have been prepared by conventional solid-state reaction. X-ray diffraction patterns revealed the formation of a single-phase cubic structure with P41 32space group. The dielectric constant of lithium ferrite increased with Mg substitution attain-ing a maximum value for x = 0.005 (ϵr= 3034, tan δ = 0.001at 1 MHz) at room temperature.Temperature-dependent dielectric response in the high frequency range (1 MHz-1 GHz)showed the relaxor behaviour of the dipoles, evident from the shift in the loss tangentwith frequency. The activation energy of LMFO is found to be in the range of 1.39 -0.35 eV. An enhanced permeability is found to be ~29 for x = 0.007 at 1 MHz, RT. The vari-ation in permeability is attributed to the variation in thickness of the domain walls andmagneto-crystalline anisotropy. The temperature-dependent magnetization curves revealthe ferrimagnetic transition of LFO at 600°C, which reduced with Mg substitution. Magnetichysteresis loops showed the highest saturation magnetization (Ms= 54.6 emu/g) for x = 0.007among all the samples. The magnetic properties are explained by considering Neel's twosub-lattice model. Thus, LMFO samples, (especially with x = 0.005) are very promising forcirculator and phase shifter applications. © 2020 The Authors.
| Item Type: | Journal Article |
|---|---|
| Publication: | Journal of Materials Research and Technology |
| Publisher: | Elsevier Editora Ltda |
| Additional Information: | The copyright for this article belongs to the Authors. |
| Keywords: | Activation energy; Domain walls; Ferrimagnetism; Ferrite; Iron compounds; Lithium; Lithium compounds; Magnesium; Magnetic materials; Microwave devices; Permittivity; Solid state reactions, Dielectric response; Electrical studies; Enhanced permeability; Lithium ferrites; Polycrystalline samples; Relaxor behaviour; Temperature dependent; Temperature-dependent magnetizations, Saturation magnetization |
| Department/Centre: | Division of Physical & Mathematical Sciences > Physics |
| Date Deposited: | 04 Jan 2023 10:24 |
| Last Modified: | 04 Jan 2023 10:24 |
| URI: | https://eprints.iisc.ac.in/id/eprint/79305 |
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