| Time：1141015 (Wed.) 14:20~16:20 Speaker：Prof.謝雅萍/ Hsieh, Ya-Ping 中央研究院原子與分子科學研究所/Institute of Atomic and Molecular Sciences, Academia Sinica Title：Pt-doped WS2 the first Extrinsic Dilute Magnetic 2D Semiconductor Abstract： Two-dimensional (2D) magnets have emerged as a promising platform for both fundamental studies of low-dimensional magnetism and the development of next-generation spintronic devices. However, intrinsic 2D magnetic materials often suffer from low Curie temperatures, environmental instability, and limited tunability, posing significant challenges for practical device integration. To overcome these limitations, extrinsic dilute magnetic semiconductors (DMS) provide an alternative route to achieving robust magnetism in 2D systems. In extrinsic DMS, a non-magnetic dopant interacts with a semiconducting host, inducing magnetic functionality without the need for intrinsic magnetic elements. This approach allows for precise control over atomic-scale interactions, making such systems ideal platforms for investigating magnetic phenomena in two dimensions. In this work, the first realization of an extrinsic 2D DMS in platinum-doped tungsten disulfide (Pt–WS₂) is reported. A bottom-up synthesis approach yields uniform and highly crystalline monolayers, in which platinum atoms selectively occupy the tungsten sublattice. Orbital hybridization between W 4d and Pt 5d states produces spin-selective electronic states, leading to a pronounced valley-Zeeman splitting. Combined experimental and theoretical studies reveal a sizable ferromagnetic response with a Curie temperature of approximately 375 K. These findings establish a novel strategy for engineering 2D magnetism through atomic-level interaction design, paving the way for future advances in spintronic devices, valleytronic applications, and magnetic nanoactuation. Place：S101, Gongguan Campus, NTNU |
