Electronic Structures of Cr-Intercalated ZrTe₂ Revealed by Angle-Resolved Photoemission Spectroscopy

Abstract

The intercalation of transition metal atoms into the van der Waals gap of the layered transition metal dichalcogenides (TMDCs) results in modulations of electronic structures and transport properties of the host materials. In order to reveal the physical mechanism of intercalation, it is essential to elucidate the band structures, especially near the Fermi level, which contributes significantly to physical properties of a solid. Taking advantage of angle-resolved photoemission spectroscopy (ARPES), we studied how Cr intercalation modifies the electronic structures of the pristine ZrTe 2 in the intercalated compound Cr 0.4 ZrTe 2 . By comparing with the semimetal band structures of ZrTe 2 , we found a nonrigid shift in the band dispersions of Cr 0.4 ZrTe 2 , in which an indirect gap opens between the valence and conduction bands with only electron-type carriers contributing to the electronic states at the Fermi level. Moreover, additional electronic states emerge below the bottom of the conduction band at M and exhibit a strong temperature-dependent behavior. Our studies show that the intercalation of atoms in van der Waals crystals could regulate the inherent band dispersions of the host materials and induce new physical properties.

The crystal structure, chemical bonding, and magnetic properties of the intercalation compounds CrxZrTe2 (x = 0–0.3)

“…In general, our results are consistent with those of [57], where the Cr 0.4 ZrTe 2 crystal was studied using ARPES. Indeed, Cr intercalation substantially changes the character of the chemical bonding in the ZrTe 2 host lattice.…”

“…This indicates a significant change in the interaction of the Zr atoms with the local environment, i.e. with the Te atoms, which can be explained by a significant distortion of the Te sublattice due to the Cr intercalation; these results are in a good agreement with those reported in [57].…”

“…This concentration is close to the percolation threshold in the sublattice of intercalated atoms (x = 0.5). This, indeed, allows us to expect those effects that were observed in [57]: 1) a strong increase in the binding energy of the valence band since at this Cr concentration each Te atom is coordinated by Cr atom; 2) a significant increase in the Fermi energy due to the charge transfer from the Cr atoms to the ZrTe 2 lattice; 3) the formation of the band of the impurity states with a pronounced dispersion (the formation of a dispersionless band of the impurity states due to a weak overlap of the orbitals of intercalated atoms is typical for the M x TCh 2 materials with low x).…”

“…At the same time, a significant (0.16 eV) shift of the Fermi level due to the Cr electrons transfer to the ZrTe 2 lattice is observed. Whereas, in [57] a similar shift was not (у Махмуда точно не было сдвига?) observed.…”

Transcriptomic, proteomic and phosphoproteomic underpinnings of daily exercise performance and Zeitgeber activity of endurance training

“…4E). Complement activation triggers tissue regeneration in response to muscle injury and inflammation (Zhang et al, 2017). Accordingly, the complement C3a, C4b, C8a, C8b, C9, CFD, and CFB proteins, were all upregulated.…”