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S. Dobrovits, B Kim, M. Reticcioli, A. Toschi, S. Khmelevskyi, C. Franchini:
"Doping-induced insulator-metal transition in the Lifshitz magnetic insulator NaOsO₃";
Journal of Physics: Condensed Matter, 31 (2019), 2440021 - 2440026.

By means of first principles schemes based on magnetically constrained density functional
theory and on the band unfolding technique we study the effect of doping on the conducting
behaviour of the Lifshitz magnetic insulator NaOsO3. Electron doping is treated within
a supercell approach by replacing sodium with magnesium at different concentrations
(MgxNa1−xOsO3, x = 0.125, 0.25, 0.375, 0.5). Undoped NaOsO3 is subjected to a temperaturedriven
Lifshitz transition involving a continuous closing of the gap due to longitudinal and
rotational spin fluctuations (Kim et al 2016 Phys. Rev. B 94 241113). Here we find that Mg
doping suppresses the insulating state, gradually drives the system to a metallic state (via an
intermediate bad metal phase) and the transition is accompanied by a progressive lowering
of the Os magnetic moment. We inspected the role of longitudinal spin fluctuations by
constraining the amplitude of the local Os moments and found that a robust metal state can be
achieved below a critical moment. In analogy with the undoped case we conjecture that the
decrease of the local moment can be controlled by temperature effects, in accordance with the
theory of itinerant electron magnetism.

DFT, metal to insulator transition, magnetism, Lifshitz, itinerant, oxides, 5d