Experimental study of the electronic and lattice contributions to the VO2 transition

Pintchovski, F.; Glaunsinger, W. S.; Navrotsky, A.

doi:10.1016/0022-3697(78)90108-7

Cited by 55 publications

(33 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is consistent with the experimental latent heat of about 44 meV including phonon contributions. [43] We would like to mention that another hint for this orbital-dependent potential comes from a study by Tomczak et al. [44] In their study, Tomczak el al.…”

Section: Tuning the Orbital Occupation Through An Orbital-dependenmentioning

confidence: 95%

See 1 more Smart Citation

VO2: Orbital competition, magnetism, and phase stability

et al. 2012

View full text Add to dashboard Cite

The relative phase stability of VO2 is one of the most fundamental issues concerning the metalinsulator transition in this material but has so far largely unexplored theoretically. We investigate the relative stability of various phases of VO2 using different levels of energy functionals within density functional theory (DFT). It is found that straightforward applications of several popular energy functionals, including the Heyd-Scuseria-Ernzerhof (HSE) hybrid functional, result in a wrong prediction for the ground state of VO2. In particular, although the HSE and DFT+U methods are able to produce a band gap in the M1 phase, they strongly favor the formation of local magnetic moments, a result that clearly disagrees with experiments. We also examine the effect of the occupation and the redistribution of the d derived t2g (i.e., dxz, dyz and d x 2 −y 2 ) orbitals of V atoms on the calculated relative phase stability of VO2. We find that a small change in d-occupation can result in a drastically different theoretical prediction. With the introduction of an orbital-dependent potential, a complete separation between the d x 2 −y 2 derived valence band and dxz and dyz derived conduction bands in the M1 phase is achieved, resulting in a slight redistribution of the d occupation and a more faithful account of the polarization of the t2g orbitals. This slight rearrangement of the d occupation also leads to a relative phase stability of VO2 (including structural and magnetic phases) that agrees well with experiment.

show abstract

Section: Tuning the Orbital Occupation Through An Orbital-dependenmentioning

confidence: 95%

“…Note that we do not consider temperature effects, therefore phonon contributions to free energy is neglected. Phonon contribution to free energy is expected to be small [43] compared with the energy differences listed in Table I.…”

Section: A Structural and Magnetic Instabilitiesmentioning

confidence: 97%

VO2: Orbital competition, magnetism, and phase stability

et al. 2012

View full text Add to dashboard Cite

show abstract

“…The closed-shell (dm) calculation correctly reproduces the experimental band gaps and provides reasonable V-V distances (2.52 and 3.16 Å compared to the experimental values 2.65 and 3.12 Å, respectively) for the monoclinic phase. [17] However, the relative energy ΔE M1 −R is qualitatively wrong (+0.38 eV instead of −0.044 eV [23] ). It has to be noted that the diamagnetic state is not the ground state of both compounds and was considered mainly for comparison.…”

Section: Pbe + Umentioning

confidence: 99%

“…The phase transition is accompanied by a change from an antiferromagnetic to a paramagnetic spin state . The heat of transition from R to M 1 was measured as −0.044 eV . The relative energy

normalΔ E_{M_{1} - R}

has been calculated as −0.008 eV with DQMC.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Critical Assessment of the DFT + U Approach for the Prediction of Vanadium Dioxide Properties

Stahl

Bredow

2019

J Comput Chem

View full text Add to dashboard Cite

In a previous study (Stahl and Bredow, Chem. Phys. Lett. 2018, 695, 28–33), we have studied structural, energetic, and electronic properties of two vanadium dioxide VO2 polymorphs with modified global and range‐separated hybrid functionals. Since hybrid methods are computationally demanding, we evaluate the computationally more efficient DFT + U method in the present study. We assessed the widely used Dudarev PBE + U approach with a literature value of the effective Hubbard parameter Ueff = 3.4 eV. We compared the PBE + U results for the two VO2 polymorphs with our previous results, a self‐consistent hybrid functional sc‐PBE0, and the meta‐GGA functional SCAN. It was found that the PBE + U method yields a strongly distorted monoclinic phase and does not reproduce the metal‐to‐insulator transition of VO2 correctly, even with modified values of Ueff. On the other hand, sc‐PBE0 and SCAN describe the relative stability and the electronic structure of both polymorphs correctly and also provide reasonable lattice parameters. The functional SCAN yields the optimal balance between computational efficiency and accuracy. © 2019 The Authors. Journal of Computational Chemistry published by Wiley Periodicals, Inc.

show abstract