Strain-tuning emergent phases in FeTe between (π,0) and (π,π) order

Iron telluride, the non-superconducting parent compound of the Fe chalcogenide materials, exhibits a peculiar (π, 0) magnetic order not seen in other iron-based superconductors, which show (π,π) magnetic order. Theoretical predictions indicate that other magnetic phases can be stabilized in Fe_1+xTe through tuning of the coupling strength between magnetic moments at next-nearest neighbor Fe sites.
Using low temperature scanning tunneling microscopy of strained samples, we have studied, at the atomic scale, the impact of small lattice distortions on the magnetic order of Fe_1+xTe (x~0.06). Straining the material along the [110] direction, we have observed a new ordered phase that is characterized by a (π, π) order. I will discuss the origin of this new phase, and show measurements of its electronic and magnetic properties.