Bo-Yao Wang

Enhanced exchange bias coupling in Fe∕FexMn1−x bilayer by reducing vertical lattice constants

The modification of crystalline structure by epitaxial growth on different single crystals induces crucial effects on the exchange bias coupling. Due to the larger lattice constant (a0) of Cu3Au(100) (a0=3.75A), the vertical lattice constants of Fe∕FexMn1−x films on Cu3Au(100) are much smaller than those of the Fe∕FexMn1−x∕Cu(100) system (Cu: a0=3.61A). By reducing the vertical lattice constants, the interface exchange bias coupling energy of Fe∕FexMn1−x∕Cu3Au(100) is enhanced to be 0.12–0.18erg∕cm2, which is approximately four times that of the Cu(100) system.

Interfacial spectroscopic characterization of organic/ferromagnet hetero-junction of 3,4,9,10-perylene-teracarboxylic dianhydride-based organic spin valves

We report interfacial characterization of 3,4,9,10-perylene-teracarboxylic dianhydride (PTCDA)-based organic spin valves (OSV) dusted with a thin layer of partially oxidized alumina at the organic semiconductor (OSC)/ferromagnet (FM) interfaces. Up to 13.5% magnetoresistance is achieved at room temperature. X-ray photoelectron spectroscopy measurements reveal interfacial electronic interaction between PTCDA and FM while the application of a thin alumina layer at the PTCDA/FM interfaces prevents the electronic hybridization and effectively preserves the spin injection into the OSC spacer. This finding demonstrates the critical effect of interfacial structure on magnetotransport behavior in OSV.

Extending the Control of Antiferromagnetic--Ferromagnetic Exchange Coupling on Perpendicular Magnetization into the Soft Magnetic Regime

Antiferromagnetic–ferromagnetic exchange coupling is known for its pinning effect on the magnetic hard layer through coercivity enhancement or exchange bias. This study reports its effect on controlling perpendicular magnetization in the soft magnetic regime. In a series of Ni78Fe22(Py)/Mn bilayers, we demonstrate that the magnetization, coercivity, and thermal stability of perpendicular anisotropy can be controlled by varying the thicknesses of the Py and Mn layers, based on the competition between the in-plane anisotropy of the Py layer and the out-of-plane-oriented Py–Mn exchange coupling. This offers a new possibility for the design of magnetic free layers in perpendicular-based magnetic logical devices.