Rotatable magnetic anisotropy in epitaxial ferrite layers

Magnetic domain structure and magnetic anisotropy were studied in monocrystalline epilayers of Mg
0.9
Mn
0.3
Fe
1.8
O
4
ferrite. The layers, several micrometers thick, were obtained by a CVD method on monocrystalline MgO substrates. Domain observations were performed by the Bitter's method. Magnetic anisotropy measurements were performed by torque and FMR methods. In the demagnetized state, a typical stripe structure of 2.0 to 2.8 μm period was observed. From the domains behavior in the in-plane magnetic fields it was found that in these epilayers the rotatable anisotropy was present. The existence of this anisotropy was confirmed by torque measurements in small in-plane fields. The magnetic parameters characterizing these layers are: 4ΠM = 3500 Gs, K
1
= - 2.2 × 10
⁴
ergs/cc, K
N
= 2.3 × 10
⁵
ergs/cc.