Manipulating surface magnetic order in iron telluride

TL;DR

This study demonstrates how surface magnetic order in iron telluride can be manipulated using low-temperature spin-polarized scanning tunneling microscopy, revealing the influence of surface excess iron on magnetic phases.

Contribution

It provides a method to control and distinguish surface magnetic structures in iron telluride by removing excess surface iron, advancing understanding of magnetic order origins.

Findings

Surface magnetic order can be manipulated by removing excess iron.

Surface excess iron influences magnetic phase behavior.

Controlled surface modification clarifies magnetic interaction mechanisms.

Abstract

Control of emergent magnetic orders in correlated electron materials promises new opportunities for applications in spintronics. For their technological exploitation, it is important to understand the role of surfaces and interfaces to other materials and their impact on the emergent magnetic orders. Here, we demonstrate for iron telluride, the nonsuperconducting parent compound of the iron chalcogenide superconductors, determination and manipulation of the surface magnetic structure by low-temperature spin-polarized scanning tunneling microscopy. Iron telluride exhibits a complex structural and magnetic phase diagram as a function of interstitial iron concentration. Several theories have been put forward to explain the different magnetic orders observed in the phase diagram, which ascribe a dominant role either to interactions mediated by itinerant electrons or to local moment interactions. Through the controlled removal of surface excess iron, we can separate the influence of the excess iron from that of the change in the lattice structure.