Oxidation and magnetic states of chalcopyrite CuFeS$_{2}$: a first principles calculation

TL;DR

This study uses density functional theory to analyze the electronic structure, oxidation, and magnetic states of chalcopyrite CuFeS2, comparing theoretical predictions with experimental data and discussing valence state complexities.

Contribution

First-principles calculations of electronic and magnetic properties of CuFeS2, providing insights into oxidation states and challenging simple valence assignments.

Findings

Predicted Cu$^{1+}$Fe$^{3+}$S$_{2}^{2-}$ oxidation state

Comparison with experimental spectroscopic data

Valence state assignment may be oversimplified

Abstract

The ground state band structure, magnetic moments, charges and population numbers of electronic shells of Cu and Fe atoms have been calculated for chalcopyrite CuFeS2 using density functional theory. The comparison between our calculation results and experimental data (X-ray photoemission, X-ray absorption and neutron diffraction spectroscopy) has been made. Our calculations predict a formal oxidation state for chalcopyrite as Cu$^{1+}$Fe$^{3+}$S$_{2}$$^{2-}$. However, the assignment of formal valence state to transition metal atoms appears to be oversimplified. It is anticipated that the valence state can be confirmed experimentally by nuclear magnetic and nuclear quadrupole resonance and M\"ossbauer spectroscopy methods.