One-step synthesis of FeSe0.45Te0.55 single crystals without excess Fe content

Excess interstitial Fe atoms in as-grown FeSe1−xTex single crystals are unavoidable in the self-flux growing procedure. As harmful defects to the study of superconductivity and Majorana fermions, the excess Fe atoms are usually removed by the post-annealing procedure. This two-step method is mostly used to obtain high quality FeSe1−xTex single crystals in present studies. Here, we carried out a one-step way to synthesize FeSe1−xTex single crystals without excess Fe content using a chemical vapor transport method. By combining transport measurement, magnetic measurement, and local scanning tunneling microscopy measurement, we prove that there is no excess Fe content in our one-step grown FeSe0.45Te0.55 single crystals. This work provides a new convenient way to obtain pure FeSe0.45Te0.55 single crystals and may be helpful to better study this exotic material.