Scanning Tunneling Microscopy of Defects in the CDW Compound Zr_0.95Hf_0.05Te₃

ZrTe₃ is a low-dimensional material that exhibits both one-dimensional and two-dimensional characteristics. Above the charge density wave (CDW) transition, bulk ZrTe₃ displays isotropic in-plane electronic conduction. However, below approximately 63 K, the material transitions into a unidirectional charge density wave (CDW) state, believed to be driven by Fermi surface nesting of two nearly parallel Fermi surface sheets originating from the long parallel Te-Te chains along the <i>a</i>-crystal axis.<br/>In this study, we present scanning tunneling microscope (STM) measurements of Hf-doped ZrTe₃, both above and below the CDW transition temperature. Using density functional theory (DFT) calculations, we simulate STM images and identify the origin of defects observed in our measurements. Additionally, we compute the cross-correlation between the defects and the CDW maxima which shows a significant pinning of the CDW to defect locations particularly at temperatures above the CDW transition.