Resonant photoemission at the absorption edge of Mn and Ti and electronic structure of 1T-Mn$_{0.2}$TiSe$_2$

TL;DR

This study uses resonant photoemission and absorption spectroscopy to analyze the electronic structure and bonding character of Mn and Ti in 1T-Mn$_{0.2}$TiSe$_2$, revealing their ionic states and localized d-states.

Contribution

First-time combined spectroscopic and theoretical analysis of Mn and Ti electronic states in 1T-Mn$_{0.2}$TiSe$_2$ revealing their ionic states and band localization.

Findings

Ti is in a 4+ ionic state.

Mn is in a 2+ ionic state.

Ti 3d states are localized near the Γ point.

Abstract

Resonant valence-band X-ray photoelectron spectra (ResPES) excited near 2p$_{3/2}$ core level energies, 2p X-ray photoelectron spectra (XPS) and L$_{3,2}$ X-ray absorption spectra (XAS) of Ti and Mn in single crystal of 1T-Mn$_2$TiSe$_2$ were studied for the first time. The ionic-covalent character of bonds formed by Mn atoms with the neighboring Se atoms in the octahedral coordination is established. From the XPS and XAS measurements compared with results of atomic multiplet calculations of Ti and Mn L$_{3,2}$ XAS it is found that Ti atoms are in ionic state of 4+ and Mn atoms are in the state of 2+. In ResPES of Mn$_{0.2}$TiSe$_2$ excited near Ti 2p$_{3/2}$ and Mn 2p$_{3/2}$ absorption edges the Ti 3d and Mn 3d bands at binding energies just below the Fermi level are observed. According to band structure calculations E$(\textbf{k})$ the Ti 3d states are localized in the vicinity of $\mathsf{\Gamma}$ point and the Mn 3d states are localized along the direction K-$\mathsf{\Gamma}$-M in the Brillouin zone of the crystal.