Structural transformations of Ru3+ trihalides

We will study structural transformations in RuCl3, RuBr3, and RuI3, the van der Waals magnets with honeycomb networks of Ru3+ ions that feature relativistic (spin-orbit-coupled) magnetic moments. These materials received attention in the context of Kitaev magnetism as possible hosts for exotic quantum states, such as quantum spin liquid. However, little is known about their structural transformations and stability regions of different polymorphs. It is also unknown at which temperature thermal decomposition of Ru3+ trihalides starts and which products it yields. This question is particularly relevant in the context of unexpected metallic-like properties that were recently reported in the nominally insulating RuCl3.