Influence of germanium substitution on the structural and electronic stability of the competing vanadium dioxide phases

Abstract

We present a density-functional theory (DFT) study of the structural, electronic, and chemical bonding behaviour in germanium (Ge)-doped vanadium dioxide (VO${}_2$). Our motivation is to explain the reported increase of the metal-insulator transition temperature under Ge doping and to understand how much of the fundamental physics and chemistry behind it can be captured at the conventional DFT level. We model doping using a supercell approach, with various concentrations and different spatial distributions of Ge atoms in VO${}_2$. Our results suggest that the addition of Ge atoms strongly perturbs the high-symmetry metallic rutile phase and induces structural distortions that partially resemble the dimerization of the experimental insulating structure. Our work, therefore, hints at a possible explanation of the observed increase in transition temperature under Ge doping, motivating further studies into understanding the interplay of structural and electronic transitions in VO${}_2$.

References in corpus (19)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Precision and efficiency in solid-state pseudopotential calculations
• Dynamical singlets and correlation-assisted Peierls transition in VO2
• Unfolding spinor wavefunctions and expectation values of general operators: Introducing the unfolding-density operator
• VO2: A Novel View from Band Theory
• Vanadium dioxide : A Peierls-Mott insulator stable against disorder
• Metal-insulator Transition in VO2: a DFT+DMFT perspective
• Resolving the VO${}_2$ controversy: Mott mechanism dominates the insulator-to-metal transition
• Effective band-structure in the insulating phase versus strong dynamical correlations in metallic VO2
• Correlation Assisted Phonon Softenings and the Mott-Peierls Transition in VO${}_2$
• Unraveling the Mott-Peierls intrigue in Vanadium dioxide
• Mind the gap but also the spin: why the Heyd-Scuseria-Ernzerhof hybrid functional description of VO2 phases is not correct
• Charge order and spin-singlet pairs formation in Ti4O7
• Charge order, orbital order, and electron localization in the Magneli phase Ti4O7
• Dynamic electronic correlation effects in NbO${}_2$ as compared to VO${}_2$
• The origin of the vanadium dioxide transition entropy
• Possible phonon-induced electronic bi-stability in VO${}_2$ for ultrafast memory at room temperature
• Fragile 3D Order in V${}_{1-x}$Mo${}_x$O${}_2$

Cited by in corpus (2)

• Single-site DFT+DMFT for vanadium dioxide using bond-centered orbitals
• Incorporating static intersite correlation effects in vanadium dioxide through DFT$+V$