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- Jönsson, Johan, et al.
(författare)
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Inverse pressure-induced Mott transition in TiPO4
- 2019
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Ingår i: Physical Review B. - : AMER PHYSICAL SOC. - 2469-9950 .- 2469-9969. ; 99:24
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Tidskriftsartikel (refereegranskat)abstract
- TiPO4 shows interesting structural and magnetic properties as temperature and pressure are varied, such as a spin-Peierls phase transition and the development of incommensurate modulations of the lattice. Recently, high-pressure experiments for TiPO4 reported two structural phases appearing at high pressures, the so-called phases IV and V [M. Bykov et al., Angew. Chem. Int. Ed. 55, 15053 (2016).]. The latter was shown to include the first example of fivefold O-coordinated P atoms in an inorganic phosphate compound. In this work, we characterize the electronic structure and other physical properties of these phases by means of ab initio calculations and investigate the structural transition. We find that the appearance of phases IV and V coincides with a collapse of the Mott insulating gap and quenching of magnetism in phase III as pressure is applied. Remarkably, our calculations show that in the high-pressure phase V, these features reappear, leading to an antiferromagnetic Mott insulating phase, with robust local moments.
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| 2. |
- Tal, Alexey, et al.
(författare)
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Pressure-induced crossing of the core levels in 5d metals
- 2016
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Ingår i: Physical Review B. - : AMER PHYSICAL SOC. - 2469-9950 .- 2469-9969. ; 93:20, s. 205150-
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Tidskriftsartikel (refereegranskat)abstract
- A pressure-induced interaction between core electrons, the core-level crossing (CLC) transition, has been observed in hcp Os at P approximate to 400 GPa [L. Dubrovinsky et al., Nature (London) 525, 226 (2015)]. By carrying out a systematic theoretical study for all metals of the 5d series (Hf, Ta, W, Re, Os, Ir, Pt, Au) we have found that the CLC transition is a general effect for this series of metals. While in Pt it occurs at approximate to 1500 GPa, at a pressure substantially higher than in Os, in Ir it occurs already at 80 GPa. Moreover, we predict that in Re the CLC transition may take place already at ambient pressure. We explain the effect of the CLC and analyze the shift of the transition pressure across the series within the Thomas-Fermi model. In particular, we show that the effect has many common features with the atomic collapse in rare-earth elements.
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