Investigation of Magnetic Properties of Zn Doped Y-Type Barium Ferrite

The Ba
₂
Co
_2-x
Zn
_x
Fe
₁₂
O
₂₂
(x = 0.0$, 0.5, 1.0, 1.5, and 2.0) polycrystalline samples were synthesized by the solid-state reaction method. Based on the Rietveld refinement, the crystal structures of samples were found to be single-phased and determined to be rhombohedral with space group of R - 3m. The unit cell volume (V
_u
) of the samples increased with increasing Zn ion concentration. In the magnetic phase diagram of Ba
₂
Co
_2-x
Zn
_x
Fe
₁₂
O
₂₂
system, samples with x ≤ 1.5 showed the spin transitions both at T
_s
and T
_C
. For x = 2.0 sample, we observed the disappearance T
_s
. The non-magnetic Zn ions preferentially occupy the tetrahedral sublattices of 6c
_IV
*, and 6c
_IV
* with down-spin site. At low temperature, this leads to the increase in M
_s
. However, the experimentally measured M
_s
at 295 K shows a slight decrease around x = 1.5. In - ddition, we have measured Mössbauer spectra of samples at various temperatures ranging from 4.2 to 750 K, which can analyzed with six-sextets for Fe sites corresponding to the 3b
_VI
, 6c
_IV
*, 6c
_VI
, 18h
_VI
, 6c
_IV
, and 3α
_VI
of the Y-type hexagonal crystallographic sites. From the Mössbauer spectra of 295 K, we observed the line-width broadening with increasing Zn concentration.