Ba$_3$Co$_0.8$Zn$_1.2$Fe$_24$O$_41$(Co$_2$Z-Type) Hexaferrite Particles for LTCC Substrates

A combination of energetic shake-milling and a subsequent double sintering process was employed to synthesize Co
_0.8
Zn
_1.2
Z (Ba
₃
Co
_0.8
Zn
_1.2
Fe
₂₄
O
₄₁
) hexaferrite nanoparticles with a high-saturation magnetization and a low coercivity. A homogeneous mixture of BaCO
₃
, CoO, ZnO, 40-nm sized alpha-Fe
₂
O
₃
, and heat-treating in an oxygen environment were important factors for synthesizing single-phase Co
₂
Z-type ferrite nanoparticles. In addition to an X-ray diffraction pattern, Mossbauer spectra confirmed that only Fe
³⁺
cations are present in the synthesized Co
_0.8
Zn
_1.2
Z particles, implying single phase of the particles. Low-temperature sintering processing, 900degC, was then successfully applied to the single-phase Co
_0.8
Zn
_1.2
Z particles. The coercivities of the Co
_0.8
Zn
_1.2
Z powder and the low-temperature sintered disk were 9 and 20 Oe, respectively, while maintaining the saturation magnetization of 50 emu/g