Effect of substrate temperature on structural, static and dynamic magnetic properties of FeSi/(001) MgO films

FeSi films with different substrate temperature (Ts) were deposited on MgO (001) substrates by a radio frequency magnetron sputtering. During the change of crystal structure from amorphous epitaxial state, magnetic anisotropy experienced three stages: dominant uniaxial magnetic anisotropy (Ts < 400 ℃) and enhanced cubic magnetocrystalline anisotropy (400 ℃ £ Ts £ 600 ℃) and weak cubic magnetocrystalline anisotropy (Ts = 700 ℃ and 800 ℃). In addition, resonance frequency ƒr firstly decreases, then reaches the maximum value, and finally disappears due to the large coercivity field. These results demonstrate the correlation between the structure, static, dynamic magnetic properties of FeSi films, and provide an effective method to prepare soft films with deterministic uniaxial or cubic magnetic anisotropy for practical application.

X-ray Photoemission Spectroscopy Study of Uniaxial Magnetic Anisotropy Induced in a Ni Layer Deposited on a LiNbO3 Substrate

The competition between magnetic shape anisotropy and the induced uniaxial magnetic anisotropy in the heterojunction between a ferromagnetic layer and a ferroelectric substrate serves to control magnetic domain structures as well as magnetization reversal characteristics. The uniaxial magnetic anisotropy, originating from the symmetry breaking effect in the heterojunction, plays a significant role in modifying the characteristics of magnetization dynamics. Magnetoelastic phenomena are known to generate uniaxial magnetic anisotropy; however, the interfacial electronic states that may contribute to the uniaxial magnetic anisotropy have not yet been adequately investigated. Here, we report experimental evidence concerning the binding energy change in the ferromagnetic layer/ferroelectric substrate heterojunction using X-ray photoemission spectroscopy. The binding energy shifts, corresponding to the chemical shifts, reveal the binding states near the interface. Our results shed light on the origin of the uniaxial magnetic anisotropy induced from the heterojunction. This knowledge can provide a means for the simultaneous control of magnetism, mechanics, and electronics in a nano/microsystem consisting of ferromagnetic/ferroelectric materials.

Slow magnetic relaxation in high-coordinate Co(ii) and Fe(ii) compounds bearing neutral tetradentate ligands

7-coordinate Co(ii) compound has a very large positive D value (56.2 cm−1) with an effective spin-reversal barrier of Ueff = 100 K (71.4 cm−1). In contrast, the 8-coordinate Fe(ii) compound exhibits uniaxial magnetic anisotropy.