Fermi surface of MoO2 studied by angle-resolved photoemission spectroscopy, de Haas-van Alphen measurements, and electronic structure calculations

TL;DR

This study combines experimental techniques and advanced electronic structure calculations to accurately characterize the Fermi surface of monoclinic MoO2, resolving previous discrepancies and highlighting the importance of precise theoretical methods.

Contribution

The paper introduces a new full-potential augmented spherical wave (ASW) method for electronic structure calculations, achieving excellent agreement with experimental data on MoO2's Fermi surface.

Findings

All Fermi surface sheets identified by experiments and calculations

Resolved previous controversies about hole-like surfaces

Demonstrated the importance of accurate calculations for transition-metal oxides

Abstract

A comprehensive study of the electronic properties of monoclinic MoO2 from both an experimental and a theoretical point of view is presented. We focus on the investigation of the Fermi body and the band structure using angle resolved photoemission spectroscopy, de Haas-van Alphen measurements, and electronic structure calculations. For the latter, the new full-potential augmented spherical wave (ASW) method has been applied. Very good agreement between the experimental and theoretical results is found. In particular, all Fermi surface sheets are correctly identified by all three approaches. Previous controversies concerning additional hole-like surfaces centered around the Z- and B-point could be resolved; these surfaces were an artefact of the atomic-sphere approximation used in the old calculations. Our results underline the importance of electronic structure calculations for the understanding of MoO2 and the neighbouring rutile-type early transition-metal dioxides. This includes the low-temperature insulating phases of VO2 and NbO2, which have crystal structures very similar to that of molybdenum dioxide and display the well-known prominent metal-insulator transitions.