Effects of Li+ and Mg2+ Dopants on the Magnetic Properties of Ni–Zn Ferrites

Ni
_0.5-0.5x
Zn
_0.5-0.5x
Mg
_x
Fe
₂
O
₄
and Ni
_0.4
Zn
_0.6-2x
Li
_x
Fe
_2+x
O
₄
ferrites (x = 0.05, 0.10, and 0.15) were prepared and examined. Both systems after sintering showed a pure spinel phase and a uniform grain size and the lattice constants declined slightly as the amount of the Mg
²⁺
and Li
⁺
dopants increased. The average grain sizes of the Ni
_0.5-0.5x
Zn
_0.5-0.5x
Mg
_x
Fe
₂
O
₄
ferrites appeared to show little variation (ranging from 4.22 to 4.55 gm), while those of the Li
⁺
-doped Ni-Zn ferrites were dramatically reduced from 5.95 to 1.40 gm corresponding to the escalation in the x values from 0 to 0.15. In terms of the magnetic properties evaluated, the Ni
_0.475
Zn
_0.475
Mg
_0.05
Fe
₂
O
₄
and Ni
_0.4
Zn
_0.4
Li
_0.10
Fe
_2.10
O
₄
ferrites demonstrated the best performance. The Ni
_0.475
Zn
_0.475
Mg
_0.05
Fe
₂
O
₄
ferrite reported a saturation magnetization of 76.9 emu/g, an initial permeability of 611.3, and a quality factor of 16.3, while the Ni
_0.4
Zn
_0.4
Li
_0.10
Fe
_2.10
O
₄
ferrite presented a saturation magnetization of 82.3 emu/g, an initial permeability of 191.3, and a quality factor of 64.3. The former is marked with a high permeability and the latter a high quality factor. These properties make them exceptionally promising for high-frequency applications.