Textured Sc-Doped Barium–Ferrite Compacts for Microwave Applications Below 20 GHz

Sc is substituted for Fe in Ba M-type hexaferrite to reduce the anisotropy field and shift the ferromagnetic resonance (FMR) frequency to below 20 GHz. We have produced pure phase BaFe
$_11$
ScO
$_19$
powders having a platelet microstructure. These materials are pressed under an applied magnetic field of 95.5
$times$
10
$^5$
A/m. Resulting compacts are sintered and are shown to have a clear uniaxial anisotropy with the
$c$
-axis perpendicular to the surface plane. Hysteresis loops display a squareness of 0.83 with a coercivity of
$sim $
186 kA/m. The
$X$
-band FMR power derivative linewidth is measured to be 79.6 kA/m.