Author(s)

Halima Akter Liya¹, Ruhina Akter¹, Abdul Ahad¹, M. N. I. Khan², M. J. Miah^1*

¹Department of Physics, Comilla University, Cumilla, Bangladesh.
²Materials Science Division, Bangladesh Atomic Energy Commission, Dhaka, Bangladesh.

The polycrystalline Li_xNi_0.2Zn_0.8-2xFe_x+2O₄ and Li_xNi_0.1Cu_0.1Zn_0.8-2xFe_x+2O₄ (x = 0.0, 0.1, 0.2, and 0.3) ferrites were synthesized by the standard solid-state reaction method. The compound was sintered at 1150˚C for 5 hours. The effect of Cu substitution and its impact on the crystal structure, microstructure, complex initial permeability and magnetization of the Ni-Zn ferrites were studied. The effect of Li⁺ incorporation on the properties mentioned above was also investigated. X-ray diffraction patterns of the samples indicated a single cubic spinel structure for both the compound. No effect of Cu addition on crystal structure was observed. The density of the ferrites was found to be enhanced because of adding Li whereas the porosity of the samples decreased with the content of Li ions. The average value of grain size increased with the addition of Li content. The samples having Cu ions formed bigger size grains. Frequency-dependent complex initial permeability, loss tangent, and relative quality factor were studied at room temperature using an Impedance analyzer in the range of 100 Hz - 120 MHz regions. In the low-frequency region, the prepared samples exhibited a high value of permeability and after a certain frequency, the permeability falls. The value of permeability enhanced with the increase in Li whereas loss tangent was found to be reduced. The relative quality factor graphs described that the compound has excellent frequency stability up to a certain frequency which is suitable to be used in inductors, resistors, capacitors, etc. Initial permeability for Li_xNi_0.1Cu_0.1Zn_0.8-2xFe_x+2O₄ ferrites was found high than Li_xNi_0.2Zn_0.8-2xFe_x+2O₄ which might be attributed to having bigger size grains of Cu containing samples because of easy movement of domain wall in bigger size grains. The values of saturation magnetization (M_s) were calculated for both compounds from M-H hysteresis loops and it enhanced with the increase in Li content which might be related to the modification of predominant exchange interactions between the cations. The Cu-containing compound exhibited higher values of saturation magnetization. The cation distribution reflects this increment because ferromagnetic Ni²⁺ and paramagnetic Cu²⁺ ions occupied in the B-sites and the diamagnetic Zn and paramagnetic Li occupied in the A-sites; therefore, net magnetic moments increased gradually. The studied materials might be used as an alternative to Pb-based compounds and would be environment friendly.

Ceramics, Ferrites, Complex Initial Permeability, Saturation Magnetization

Liya, H. , Akter, R. , Ahad, A. , Khan, M. and Miah, M. (2021) Effect of Cu Incorporation on Structure, Densification and Magnetic Properties of Polycrystalline Li_xNi_0.2Zn_0.8-2xFe_2+xO₄ Ceramics. Journal of Applied Mathematics and Physics, 9, 3211-3229. doi: 10.4236/jamp.2021.912210.