Shock‐induced phase transition of MnO around 90GPa

Noguchi, Yuichi; Kusaba, Keiji; Fukuoka, Kazuya; Syono, Yasuhiko

doi:10.1029/96gl01326

Cited by 38 publications

(20 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Shock wave compression experiments on MnO have revealed that it undergoes an 8% volume collapse at a pressure of 90 GPa and an estimated temperature of 1000°C on the shock Hugoniot P-V curve. 12 Electrical conductivity experiments on MnO under shock compression up to 50 GPa revealed no evidence of metallization to this pressure. 13 In addition, recent simulations predict magnetic collapse 3 in MnO at 149 GPa, and stabilization of the metallic B8 ͑NiAs͒ phase 14 at pressures above 120 GPa.…”

Section: Introductionmentioning

confidence: 90%

Pressure-induced metallization of the Mott insulatorMnO

et al. 2004

View full text Add to dashboard Cite

High-pressure electrical conductivity experiments have been performed on the Mott insulator MnO to a maximum pressure of 106 GPa. We observe a steady decrease in resistivity to 90 GPa, followed by a large, rapid decrease by a factor of 10 5 between 90 and 106 GPa. Temperature cycling the sample at 87 and 106 GPa shows insulating and metallic behavior at these pressures, respectively. Our observations provide strong evidence for a pressure-induced insulator-to-metal transition beginning at 90 GPa.

show abstract

Section: Introductionmentioning

confidence: 90%

Pressure-induced metallization of the Mott insulatorMnO

et al. 2004

View full text Add to dashboard Cite

show abstract

“…The classic Mott insulator, MnO, exhibits metalization under pressure. This phase transition is accompanied by a simultaneous moment and volume collapse [3][4][5][6][7][8]. On the theory side, however, the physics of this phase transition is totally different for different methods; while DFT results indicate that the increase in band width controls the phase transition[9, 10] DMFT results, on the other hand, show that the main reason for metalization lies in the increased crystal field splitting[1].…”

mentioning

confidence: 99%

Spectral Density and Metal-Insulator Phase Transition in Mott Insulators within Reduced Density Matrix Functional Theory

et al. 2013

View full text Add to dashboard Cite

We present a method for calculating the spectrum of periodic solids within reduced density matrix functional theory. This method is validated by a detailed comparison of the angular momentum projected spectral density with that of well established many-body techniques, in all cases finding an excellent agreement. The physics behind the pressure induced insulator-metal phase transition in MnO is investigated. The driving mechanism of this transition is identified as increased crystal field splitting with pressure, resulting in a charge redistribution between the Mn eg and t2g symmetry projected states. PACS numbers:Transition metal oxides (TMOs), the prototypical Mott insulators, are test-bed systems for new functionals within density functional theory (DFT) and manybody theories alike. Ground state spectra obtained from many-body theories are in good agreement with experiments. Moreover, the spectral density obtained using dynamical mean field theory (DMFT) [1] and the G 0 W 0 corrected DFT[2] agree with each other even for subtle features such as symmetry and site projected spectral density. Single particle DFT spectra can also be made to agree with these many-body results by using two separate fitting parameters; the on-site Coulomb term U and the scissors shift ∆, where ∆ is the difference between the experimental gap and the Kohn-Sham gap obtained using the LSDA+U functional [2].Away from the ground-state TMOs show the rich physics of insulator-metal phase transitions. The classic Mott insulator, MnO, exhibits metalization under pressure. This phase transition is accompanied by a simultaneous moment and volume collapse [3][4][5][6][7][8]. On the theory side, however, the physics of this phase transition is totally different for different methods; while DFT results indicate that the increase in band width controls the phase transition[9, 10] DMFT results, on the other hand, show that the main reason for metalization lies in the increased crystal field splitting[1].Recently, RDMFT has shown potential for correctly treating Mott insulators under ambient conditions [11,12]. RDMFT is an appealing alternative since it does not require any system dependent parameters and thus is a truly ab-initio theory for treating strong correlations. However, it still remains to be seen how RDMFT performs away from ambient pressure conditions; can RDMFT capture the insulator-metal phase transition? What is the physics of this phase transition within RDMFT? In order to answer these questions one requires two things: (1)a magnetic extension of RDMFT and (2) information about photo-emission spectrum to shed light on the nature of the phase transition. The latter is a difficult quantity to extract from RDMFT which, by its very nature, is a ground-state theory.In the present work we extend RDMFT to describe magnetic solids and further present a technique for calculating the photo-emission spectrum. We validate this technique by demonstrating an excellent agreement of the t 2g and e g resolved spectral density thus obtained, with the ...

show abstract

“…MnO crystallizes in the rock-salt structure and exhibits AFM order below 118 K. The shock data [16], and later Raman and optical studies [17], had identified a transformation in MnO in the neighborhood of 90-105 GPa. Transport [18], magnetic, structural and spectroscopic [19], and reflectivity [17] data all point to a first-order, insulator-metal Mott transition near 100 GPa with volume (v = V/V 0 ) collapse v = 0.68 → 0.63, and moment collapse (from ∼ 5μ B to 1μ B or less [19]).…”

Section: Mnomentioning

confidence: 96%

Various scenarios of metal‐insulator transition in strongly correlated materials

Kuneš

Анисимов

2011

Annalen der Physik

View full text Add to dashboard Cite

This article is dedicated to Dieter Vollhardt on the occasion of his 60th birthday.We review our investigations of electronic properties of strongly correlated materials using the combination of first principles electronic band structures and the dynamical mean-field theory, so called LDA+DMFT method. Our investigations focus on two phenomena, the spin state transitions and their relationship to the metal-insulator transition, and the effect of hybridization between correlated and ligand orbitals in chargetransfer type materials. The pressure driven spin transitions are studied for a group of materials containing MnO, FeO and Fe2O3. To investigate the hybridization effects we focus on NiO and NiS(Se)2. We identify various mechanisms of the metal-insulator transition, which can take place in multi-band systems, in addition to the band-width control known from the single band Hubbard model.

show abstract

Shock‐induced phase transition of MnO around 90GPa

Cited by 38 publications

References 20 publications

Pressure-induced metallization of the Mott insulatorMnO

Pressure-induced metallization of the Mott insulatorMnO

Spectral Density and Metal-Insulator Phase Transition in Mott Insulators within Reduced Density Matrix Functional Theory

Various scenarios of metal‐insulator transition in strongly correlated materials

Contact Info

Product

Resources

About