Transition metals dihalides: from 2D magnetism to metal-organic hybrids

日時　2024年11月25日　（月）　14:00～15:30
場所　WPI-SKCM2研究棟（VBL）　2階　セミナー室（VBL204）
講師　Martina Corso
(Center for Materials Physics, San Sebastian, Spain）

Transition metals dihalides are an ideal class of van der Waals layered materials that enable the study of magnetic phases as function of the transition metal and halide composition as predicted by theory. Here, we characterize two-dimensional magnets based on metallic dichlorides. The materials can be epitaxially grown on different substrates in ultra-high vacuum. By X-Ray Magnetic Circular Dichroism (XMCD) measurements we find that single layers of FeCl₂ and NiCl₂ are soft ferromagnets on Au(111) and their magnetization can be switched from out-of-plane to in-plane by substituting the metal ion from Fe to Ni. Using low temperature scanning tunneling microscopy (STM) with tips functionalized with a nickelocene molecule as magnetic sensor, we confirm the magnetic order of the materials at the atomic scale even at zero applied magnetic field. Our results suggest that these 2D semiconducting magnets could be implemented in van der Waals heterostructures for applications in spintronics and opto-spintronics.

A further use we give to transition metals dihalides is to grow hybrid metal-graphene nanoribbons (GNRs) systems by on surface chemistry. By combing several surface science techniques we study the potential of using edge functionalized chiral GNRs with or without metal coordination for precise gas sensing applications

問合せ先　奥田太一、出田真一郎（放射光研究所）