Crystal growth, characterization and electronic band structure of TiSeS

Abstract

Layered semimetallic van der Waals material $\mathrm{Ti}{\mathrm{Se}}_{2}$ has attracted a lot of attention because of interplay of a charge density wave (CDW) state and superconductivity. Its sister compound ${\mathrm{TiS}}_{2}$, being isovalent to $\mathrm{Ti}{\mathrm{Se}}_{2}$ and having the same crystal structure, shows a semiconducting behavior. The natural question rises---what happens at the transition point in $\mathrm{Ti}{\mathrm{Se}}_{2\ensuremath{-}x}{\mathrm{S}}_{x}$, which is expected for x close to one. Here we report the growth and characterization of TiSeS single crystals and the study of the electronic structure using density functional theory (DFT) and angle-resolved photoemission (ARPES). We show that TiSeS single crystals have the same morphology as $\mathrm{Ti}{\mathrm{Se}}_{2}$. Transport measurements reveal a metallic state; no evidence of CDW was found. DFT calculations suggest that the electronic band structure in TiSeS is similar to that of $\mathrm{Ti}{\mathrm{Se}}_{2}$, but the electron and hole pockets in TiSeS are much smaller. The ARPES results are in good agreement with the calculations.