Atomic to mesoscale hierarchical structures and magnetic states in an anisotropic layered ferromagnet FePd2Te2

TL;DR

This study investigates the hierarchical atomic to mesoscale structures and magnetic states of the in-plane anisotropic 2D ferromagnet FePd2Te2, revealing how twinning domains influence its magnetic behavior and phase transitions.

Contribution

It provides the first real-space analysis of twinning structures and magnetic states in FePd2Te2, linking atomic-scale features to mesoscale magnetic properties and phase diagrams.

Findings

Hierarchical atomic to mesoscale structures observed with AFM/MFM and STM.

Identification of structure-related ferromagnetic and polarized-FM states.

Development of a comprehensive H-T phase diagram for FePd2Te2.

Abstract

Two-dimensional (2D) magnetic materials have predominantly exhibited easy-axis or easy-plane anisotropy and display a high sensitivity to the underlying crystal structure and lattice symmetry. Recently, an in-plane anisotropic 2D ferromagnet of FePd2Te2 has been discovered with intriguing structure and quasi-one-dimensional spin system. Here, we report a real-space investigation of its twinning structure and magnetic states using atomic/magnetic force microscopy (AFM/MFM) combined with scanning tunneling microscopy (STM). The atomic to mesoscale hierarchical structures with the orthogonal and corrugated compressive /tensile(C/T) regions are directly observed due to the intrinsic twinning-domain characteristic. The structure-related intact ferromagnetic (FM), field-induced polarized-FM states and their transitions are comparatively discussed at the mesoscale with the corresponding macroscopic magnetic measurements. Temperature- and field-dependent evolution of magnetic phase are further investigated at the FM and PM states, and summarized to obtain a unique H-T phase diagram of FePd2Te2. Our work provides key results for understanding the complicated magnetic properties of FePd2Te2, and suggests new directions for manipulating magnetic states through the atomic and mesoscale structure engineering.