Abstract <p>The alloys of the TlInTe₂–Fe system were studied by differential thermal analysis, X-ray diffraction, and microstructural analysis. The solubility range of iron in the TlInTe₂ compound was determined to be 5.0 at % at 296 K. Solid solutions formed on the basis of the ternary compound TlInTe₂ in the TlInTe₂–Fe system are predominantly interstitial solid solutions, with iron atoms located mainly in the octahedral voids along the <i>c</i> axis between thallium ions. The appearance of a new mode at ~120 cm^–1 in the Raman scattering spectra of single-crystal TlInTe₂ samples doped with 5.0 at % Fe was observed. It was found that the incorporation of iron atoms into the TlInTe₂ crystal lattice lowers the activation energy of impurity conductivity and increases the crystal’s conductivity due to the rise in charge carrier concentration.</p>