Evolution of the Magnetic Excitations in NaOsO3 through its Metal-Insulator Transition

Abstract

The temperature dependence of the excitation spectrum in NaOsO_{3} through its metal-to-insulator transition (MIT) at 410 K has been investigated using resonant inelastic x-ray scattering at the Os L_{3} edge. High-resolution (ΔE∼56 meV) measurements show that the well-defined, low-energy magnons in the insulating state weaken and dampen upon approaching the metallic state. Concomitantly, a broad continuum of excitations develops which is well described by the magnetic fluctuations of a nearly antiferromagnetic Fermi liquid. By revealing the continuous evolution of the magnetic quasiparticle spectrum as it changes its character from itinerant to localized, our results provide unprecedented insight into the nature of the MIT in NaOsO_{3} [J. G. Vale, S. Calder, C. Donnerer, D. Pincini, Y. G. Shi, Y. Tsujimoto, K. Yamaura, M. M. Sala, J. van den Brink, A. D. Christianson, and D. F. McMorrow, Phys. Rev. B 97, 184429 (2018)PRBMDO2469-995010.1103/PhysRevB.97.184429].

Origin of magnetic excitation gap in double perovskite Sr2FeOsO6

“…The high resolution RIXS data were fit with a Gaussian peak shape, giving excited state energies of 0.723(3), 0.934(3), 1.34(1) and 1.52(2) eV at 6 K. This compares with 0.745(7), 0.971(7), 1.447(9) and 1.68(1)eV from Ref. [3], other related 5d containing double perovskite systems [30,31] and for NaOsO 3 [32,33].…”

Spin and orbital excitations through the metal-to-insulator transition in Cd2Os2O7 probed with high-resolution resonant inelastic x-ray scattering

“…This would have ramifications for the analysis of orbital excitations in other systems proximate to a metal-insulator transition, and ties in with the description of magnetic excitations in the itinerant and localized regimes. 29…”

Aberrant electronic and structural alterations in pressure tuned perovskite NaOsO3

“…Initially, a Slater-like mechanism was proposed to explain this unusual MIT behavior 4 . Subsequent insights have revealed that this transition is better interpreted by a relativistic magnetic Lifshitz mechanism where MIT is driven by magnetic fluctuations and spin-orbit-induced renormalization of the electron correlation 7,8 .…”

“…Strikingly, we discovered that, without increasing the temperature, the orthorhombic phase of NaOsO 3 could transform into a polar perovskite phase with a space group of Pna2 1 , which violates the general trend of the perovskite oxides and has only been detected in PbRuO 3 (Pbnm → Pbn2 1 ) 19 and LiOsO 3 (R3c → R3c) 20 so far. The latter two materials are nonmagnetic, while NaOsO 3 has obvious magnetic properties [2][3][4][5][6][7][8][9] and preserves the band gap during the transition with a slow reduction of the MIT towards lower temperatures (T < 410 K). In addition, compression of NaOsO 3 manifests much more complicated emergent structural and electronic phenomena, which could be only characterized by using multiple techniques, such as electrical transport, Raman, synchrotron x-ray diffraction techniques (XRD), and first-principles calculations that are applied in this study.…”