Field-free spin-orbit torque switching in interlayer exchange coupled Co/Ta/CoTb.

This study investigates a T-type field-free spin-orbit torque device with an in-plane magnetic layer coupled to a perpendicular magnetic layer via a non-magnetic spacer. The device utilizes a Co/Ta/CoTb structure, in which the in-plane Co layer and the perpendicular CoTb layer are ferromagnetically (FM) coupled through the Ta spacer. 'T-type' refers to the magnetization arrangement in the FM/spacer/FIM structure, where the magnetization in FM is in-plane, while in FIM, it is out-of-plane. This configuration forms a T-shaped arrangement for the magnetization of the two magnetic layers. Additionally, 'interlayer exchange coupling (IEC)' denotes the interaction between the two magnetic layers, which is achieved by adjusting the material and thickness of the spacer. Our results show that an in-plane effective field from the IEC enables deterministic current-induced magnetization switching of the CoTb layer. The field-driven and the current-driven asymmetric domain wall motion are observed and characterized by magneto-optic Kerr effect measurements. The functionality of multistate synaptic plasticity is demonstrated by understanding the relationship between the anomalous Hall resistance and the applied current pulses, indicating the potential for the device in spintronic memory and neuromorphic computing.

Rising from the Ashes: Gaseous Therapy for Robust and Large-Area Perovskite Solar Cells.

Scalable fabrication of perovskite solar cells (PSCs) with high reliability is one of the most pivotal concerns that must be addressed before they get into the photovoltaic (PV) market. Scaling large-area high-quality perovskite films is of great importance in this process. Here, gaseous therapy has been proposed for the post-treatment of perovskite films with high scalability and low cost. An inspiring evolvement from poor perovskite films to high quality ones is demonstrated under a joint treatment of methylamine gas and hot solvent vapors. The perovskite films are completely reconstructed and repaired regardless of the morphology of the original films. As a consequence, small-area (0.09 cm2) and large-area (4 cm2) PSCs based on the healed MAPbI3 films can afford J-V scanned efficiencies of 19.2 and 16.5% under a reverse sweep, respectively. Furthermore, stabilized power outputs of 18.5 and 15.2% are obtained from the small one and large one under continuous maximum power point tracking.