SCALE-ICE · Investigation of Spin, Charge and Lattice Coupling Effects in Van der Waals Crystals in an electron microscope

Lattice structures are ubiquitous in nature, which determine diverse physical and chemical properties of materials. Exploring and controlling crystal structures is a central task of material engineering. Lattice phase transition is considered as a significant approach to manipulate and control functionalities, and thus, understanding the underlying mechanism of phase transition is a basic premise and guarantee for technological applications. A fundamental understanding of the cooperative interplay between charge, spin, orbital and lattice is required to manipulate this process. The emergence of magnetic Van der Waals (vdW) crystals opened up new horizons for engineering phase transition with magnetic orders together beyond the reach of existing materials. Traditional investigation of magnetic phase transition requires neutron diffraction, which requires nuclear reactor to generate neutrons. In this project, I propose to use three-dimensional electron diffraction (3DED) to study the 3D magnetic orderings, which will serve as a complimentary method to neutron diffraction. I will also study the dynamical behaviour of magnetic ordering in vdW crystals under different electric bias conditions. In addition, I will study the 3D magnetic field distribution at the interface of heterostructures constructed by vdW crystals. I will develop continuous fast holographic tomography (CFHT) with much lower dose and higher speed compared to traditional step-wise tomography. I will also apply a special 3D reconstruction algorithm to reveal and visualize the 3D magnetic field at the heterostructure interface. The outputs of this project will provide insight into the synergy effects of charge, spin and lattice in magnetic materials and greatly facilitate the discovery of novel magnetic materials.