Pressure-induced insulator–metal transition in EuMnO₃

Abstract

We study the influence of external pressure on the electronic and magnetic structure of EuMnO3 from first-principles calculations. We find a pressure-induced insulator-metal transition at which the magnetic order changes from A-type antiferromagnetic to ferromagnetic with a strong interplay with Jahn-Teller distortions. In addition, we find that the non-centrosymmetric E * -type antiferromagnetic order can become nearly degenerate with the ferromagnetic ground state in the high-pressure metallic state. This situation can be exploited to promote a magnetically-driven realization of a non-centrosymmetric (ferroelectric-like) metal.

Strain-induced heteronuclear charge disproportionation in EuMnO3

“…We note that while with the Eu f electrons in the core as in Ref. 34, U Mn =2 eV results in the correct A-AFM magnetic structure (see Figure A3a), we find that with the f electrons in the valence, FM alignment of the Mn moments is slightly favoured, independently of the value of U Mn and U Eu and the nature of the Eu magnetic order (see supporting Figure A3b and c). This highlights the commonly observed delicate dependence of AFM → FM Mn transitions in the rare-earth manganites on the computational setup 35 .…”

“…We applied a Dudarev 33 DFT+U correction to both the Eu f and Mn d states. It was previously shown that U Mn has an effect on the pressure dependence of the magnetic ground state 34 , with U Mn values of 1 and 2 eV giving the same qualitative results but quantitatively different antiferromagnetic to ferromagnetic transition pressures. We found that U Mn also has a marked effect on the charge ground state, with U Mn = 1 and 3 eV resulting in the 2-4 and 3-3 ground states respectively.…”

Magnetic properties of La0.7Sr0.3MnO3 under the pressure and the transport property under the magnetic field

“…For example, the A-type antiferromagnetic (AFM) insulating systems LaMnO 3 and EuMnO 3 undergo a transition from an AFM insulator to a ferromagnetic metallic phase under the pressure. [48][49][50] The T c of La 0.82 Ca 0.18 MnO 3 single crystal increases with pressure 41 with the pressure coefficient dT c / dP being about 3-4 K/GPa and the concomitant increase in magnetization below T c . 51 For the ferromagnetic insulating Sm 0.7 Sr 0.3 MnO 3 polycrystal, its T c does not change obviously with pressure, whereas the pressure increases T c of Sm 0.6 La 0.1 Sr 0.3 MnO 3 with the ferromagnetic metallic ground state.…”

“…The pressure, just like the temperature and the magnetic field, as a clean and effective means, on the one hand, it can be used to control the electrical/magnetic properties of perovskite manganites, on the other hand, in principle, it can regulate the J‐T distortion, making it possible to find the novel phenomena and to reveal the physical mechanism. For example, the A‐type antiferromagnetic (AFM) insulating systems LaMnO 3 and EuMnO 3 undergo a transition from an AFM insulator to a ferromagnetic metallic phase under the pressure 48‐50 . The T c of La 0.82 Ca 0.18 MnO 3 single crystal increases with pressure 41 with the pressure coefficient d T c /d P being about 3‐4 K/GPa and the concomitant increase in magnetization below T c 51 .…”

Comparative study of nonequilibrium insulator-to-metal transitions in electron-phonon systems

“…In such systems, changes in thermodynamic parameters may induce insulator-to-metal transitions (IMTs), as has been demonstrated by varying temperature 1 or pressure. 2,3 Laser-induced mechanisms provide another strategy to manipulate quantum phases in these materials. [4][5][6][7] In these experiments, phase transitions or transitions to metastable states are induced by a time-dependent perturbation.…”