Structural and Morphological Modifications Induced by Fe Ion Implantation in Sb2Te3 Thin Films

Abstract Recently, considerable interest has been initiated by the influence of magnetic dopants as well as the generation of internal strain on the transport properties of topological insulators. The controlled bulk charge carriers in topological insulators help in removing barriers for surface‐dominated transport. In this work, the impact of Fe‐ion implantation on the structural and optical properties of Sb 2 Te 3 thin films is presented. The implantation is done with low energy Fe 4– ions at three different fluences (1 × 10 13 , 1 × 10 14 , and 5 × 10 14 ions cm −2 ). The structural studies carried out using X‐ray diffraction measurements show that the thin films exhibit rhombohedral structures with an R‐3m space group. A monotonic decrease in the lattice parameter “ c ” is also observed with increasing ion fluence confirms the contraction in lattice after implantation with ions of smaller radii. The optical studies indicate the structural strain induces by implantation. The incorporated Fe ion affects the grain size, as studied by Atomic Force Microscopy (AFM) measurements. The suppression of grain boundaries towards the highest fluence point is towards a possibility of surface reconstruction.