Magnetic collapse and the behavior of transition metal oxides at high pressure

Leonov, I.; Pourovskii, L. V.; Georges, Antoine; Abrikosov, Igor A.

doi:10.1103/physrevb.94.155135

Cited by 54 publications

(70 citation statements)

References 89 publications

(73 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this work, we provide a detailed theoretical study of the electronic structure, magnetic state, and phase stability of paramagnetic B1-structured (Fe,Mg)O using a fully charge self-consistent implementation of the DFT + DMFT method [50][51][52][53][68][69][70]. We use this advanced theory to compute the high-pressure and -temperature properties of (Fe,Mg)O as a function of Mg content x in the range between 0 and 0.875, i.e., above the percolation limit (∼12% Fe) of the fcc lattice of B1 type (Fe,Mg)O [72].…”

Section: Methodsmentioning

confidence: 99%

“…We employ the DFT + DMFT approach implemented within the plane-wave pseudopotentials [68][69][70] with the generalized gradient approximation in DFT [78,79]. For the partially filled Fe 3d and O 2p orbitals we construct a basis set of Wannier functions [80,81] using the projection procedure on a local atomic-centered symmetry-constrained basis set as discussed in Refs.…”

Section: Methodsmentioning

confidence: 99%

“…The DFT + DMFT method [50][51][52][53] allows one to capture all generic aspects of a pressure-induced Mottinsulator-to-metal phase transition (MIT), such as coherent quasiparticle behavior, the formation of the lower and upper Hubbard bands, and strong renormalization of the effective electron mass (reduced electron mobility) [54][55][56][57][58][59][60][61][62][63][64][65][66]. Most importantly, applications of DFT + DMFT have been shown to provide a good qualitative and even quantitative description of the electronic structure and phase stability of correlated materials, even in the vicinity of a MIT [67][68][69][70][71].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Pressure-induced spin-state transition of iron in magnesiowüstite (Fe,Mg)O

et al. 2017

Self Cite

View full text Add to dashboard Cite

We present a detailed theoretical study of the electronic, magnetic, and structural properties of magnesiowüstite Fe 1−x Mg x O with x in the range between 0 and 0.875 using a fully charge self-consistent implementation of the density functional theory plus dynamical mean-field theory method. In particular, we compute the electronic structure and phase stability of the rocksalt B1-structured (Fe,Mg)O at high pressures relevant for the Earth's lower mantle. We find that upon compression paramagnetic (Fe,Mg)O exhibits a spin-state transition of Fe 2+ions from a high-spin to low-spin (HS-LS) state which is accompanied by a collapse of local magnetic moments. The HS-LS transition results in a substantial drop in the lattice volume by about 4%-8%, implying a complex interplay between electronic and lattice degrees of freedom. Our results reveal a strong sensitivity of the calculated transition pressure P tr. upon addition of Mg. While, for Fe-rich magnesiowüstite with Mg x < 0.5, P tr. is about 80 GPa, for Mg x = 0.75 it drops to 52 GPa, i.e., by 35%. This behavior is accompanied by a substantial change in the spin transition range from 50 to 140 GPa in FeO to 30 to 90 GPa for x = 0.75. In addition, the calculated bulk modulus (in the HS state) is found to increase by ∼12% from 142 GPa in FeO to 159 GPa in (Fe,Mg)O with Mg x = 0.875. We find that the pressure-induced HS-LS transition has different consequences for the electronic properties of the Fe-rich and -poor (Fe,Mg)O. For the Fe-rich (Fe,Mg)O, the transition is found to be accompanied by a Mott insulator to a (semi)metal phase transition. In contrast to that, for x > 0.25, (Fe,Mg)O remains insulating up to the highest studied pressures, implying a Mott-insulator to band-insulator phase transition at the HS-LS transformation.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Pressure-induced spin-state transition of iron in magnesiowüstite (Fe,Mg)O

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…The CF splitting is typically controlled by external or chemical pressure. Spin-state crossovers were observed in many oxides of transition metals from the middle of the periodic table such as MnO, Fe 2 O 3 , FeO, CoO, which were theoretically studied with the LDA+DMFT approach [34,[83][84][85][86][87]. In bulk materials it usually gives rise to a smooth crossover or a first order transition, and often involves a sizeable change of the specific volume.…”

Section: Computation Of Susceptibilities Within Dmftmentioning

confidence: 99%

“…Recently it was employed to explore the electronic properties and the phase stability of paramagnetic V 2 O 3 [29] and the transition metal monoxides MnO, FeO, CoO, and NiO near the pressure-induced Mott-Hubbard metal-insulator transition [87].…”

Section: Structural Stability Of Correlated Materialsmentioning

confidence: 99%

LDA+DMFT approach to ordering phenomena and the structural stability of correlated materials

Kuneš

Leonov

Augustinský

et al. 2017

Eur. Phys. J. Spec. Top.

Self Cite

View full text Add to dashboard Cite

Abstract. Materials with correlated electrons often respond very strongly to external or internal influences, leading to instabilities and states of matter with broken symmetry. This behavior can be studied theoretically either by evaluating the linear response characteristics, or by simulating the ordered phases of the materials under investigation. We developed the necessary tools within the dynamical mean-field theory (DMFT) to search for electronic instabilities in materials close to spin-state crossovers and to analyze the properties of the corresponding ordered states. This investigation, motivated by the physics of LaCoO 3, led to a discovery of condensation of spinful excitons in the two-orbital Hubbard model with a surprisingly rich phase diagram. The results are reviewed in the first part of the article. Electronic correlations can also be the driving force behind structural transformations of materials. To be able to investigate correlation-induced phase instabilities we developed and implemented a formalism for the computation of total energies and forces within a fully charge self-consistent combination of density functional theory and DMFT. Applications of this scheme to the study of structural instabilities of selected correlated electron materials such as Fe and FeSe are reviewed in the second part of the paper.

show abstract

Magnetic and Electronic Properties of Complex Oxides from First‐Principles

Hoffmann

Ernst

Hergert

et al. 2020

Physica Status Solidi (b)

View full text Add to dashboard Cite

The theoretical treatment of complex oxide structures requires a combination of efficient methods to calculate structural, electronic, and magnetic properties, due to special challenges such as strong correlations and disorder. In terms of a multicode approach, this study combines various complementary first‐principles methods based on density functional theory to exploit their specific strengths. Pseudopotential methods, known for giving reliable forces and total energies, are used for structural optimization. The optimized structure serves as input for the Green's function and linear muffin‐tin orbital methods. Those methods are powerful for the calculation of magnetic ground states and spectroscopic properties. Within the multicode approach, disorder is investigated by means of the coherent potential approximation within a Green's function method or by construction of special quasirandom structures in the framework of the pseudopotential methods. Magnetic ground states and phase transitions are studied using an effective Heisenberg model treated in terms of a Monte Carlo method, where the magnetic exchange parameters are calculated from first‐principles. The performance of the multicode approach is demonstrated with different examples, including defect formation, strained films, and surface properties.

show abstract

Magnetic collapse and the behavior of transition metal oxides at high pressure

Cited by 54 publications

References 89 publications

Pressure-induced spin-state transition of iron in magnesiowüstite (Fe,Mg)O

Pressure-induced spin-state transition of iron in magnesiowüstite (Fe,Mg)O

LDA+DMFT approach to ordering phenomena and the structural stability of correlated materials

Magnetic and Electronic Properties of Complex Oxides from First‐Principles

Contact Info

Product

Resources

About