In-Plane Transverse Susceptibility of (111)-Oriented Iron Garnet Films

Iron garnet films with various compositions Y
₃
Fe
₅
O
₁₂
(YIG), (LuPr)
₃
Fe
₅
O
₁₂
(LuPrIG), and Tm
₃
(FeSc)
₅
O
₁₂
(TmScIG) were grown by liquid phase epitaxy on gadolinium gallium garnet substrates. The angular dependences of in-plane transverse magnetic susceptibility χ'(φ) were investigated to estimate their applicability as a fluxgate core. The χ'(φ) dependence permitted the determination of the anisotropy field H
_C
in the film plane. Experimentally obtained values of H
_C
show good agreement with theoretical values and correspond to 2.5, 0.92, and 0.03 Oe for YIG, LuPrIG, and TmScIG epitaxial films, respectively. The influence of garnet composition on mechanisms of decreasing of induced in-plane anisotropy field was determined. TmScIG films exhibit about 100-fold reduction in the anisotropy in the plane of the film as compared with films of pure YIG.