Theoretical Studies of the Structure and Stability of Metal Chalcogenide CrnTem (1≤n≤6, 1≤m≤8) clusters

Author

FNU Sweta Prabha, Virginia Commonwealth UniversityFollow

DOI

https://doi.org/10.25772/YKFX-M918

Defense Date

2019

Document Type

Thesis

Degree Name

Master of Science

Department

Physics and Applied Physics

First Advisor

Shiv N Khanna

Abstract

In the presented work, first principle studies on electronic structure, stability, and magnetic properties of metal chalcogenide, Cr_nTe_m clusters have been carried out within a density functional framework using generalized gradient functions to incorporate the exchange and correlation effects. The energetic and electronic stability was investigated, and it was found that they are not always correlated as seen in the cluster Cr₆Te₈ which has smaller gap between its HOMO (Highest Occupied Molecular Orbital) and LUMO (Lowest Unoccupied Molecular Orbital) and a high electron affinity of 3.39 eV indicating lower electronic stability whereas higher fragmentation energy indicating energetic stability. The high electron affinity shows that the stability of Cr₆Te₈ cluster can be enhanced by adding charge donating ligands including PEt₃ to form stable Cr₆Te₈(PEt₃)₆ clusters as seen in experiments. The other cluster of interest was Cr₄Te₆ in which energetic stability was accompanied with electronic inertness marked by its large HOMO-LUMO gap, non-magnetic ground state and high fragmentation energy.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

5-3-2019