Anisotropic magnetic excitations and incipient Néel order in Ba(Fe${}_{1-x}$Mn${}_x$)${}_2$As${}_2$

Abstract

It is currently understood that high temperature superconductivity (SC) in the transition metal $(M)$ substituted iron arsenides Ba(Fe${}_{1-x}$$M$${}_x$)${}_2$As${}_2$ is promoted by magnetic excitations with wave vectors $(\pi ,0)$ or $(0,\pi )$. It is known that while a small amount of Co substitution leads to SC, the same does not occur for Mn for any value of $x$. In this work, magnetic excitations in the iron arsenides Ba(Fe${}_{1-x}$Mn${}_x$)${}_2$As${}_2$ ($x=0.0$, $0.007$, $0.009$, $0.08$) are investigated by means of Resonant Inelastic X rays Scattering (RIXS) at the Fe $L_3$-edge, for momentum transfer $\mathbf{q}$ along the high symmetry Brillouin zone $(\pi ,0)$ and $(\pi ,\pi )$ directions. It is shown that with increasing Mn content ($x$), the excitations become anisotropic both in dispersion and lineshape. Both effects are detected even for small values of $x$, evidencing a cooperative phenomenon between the Mn impurities, that we ascribe to emerging Néel order of the Mn spins. Moreover, for $x=0.08$, the excitations along $\mathbf{q}\parallel (\pi ,0)$ are strongly damped and nearly non dispersive. This result suggests that phases of arsenides containing local moments at the FeAs layers, as in Mn or Cr substituted phases, do not support high temperature SC due to absence of the appropriate magnetic excitations.

7 pages, 5 figures, accepted in Physical Review B

References in corpus (17)

• Spin density wave anomaly at 140 K in the ternary iron arsenide BaFe2As2
• Near-degeneracy of several pairing channels in multiorbital models for the Fe-pnictides
• Coherence-incoherence crossover in the normal state of iron-oxypnictides and importance of the Hund's rule coupling
• Iron-Based Superconductors: current status of materials and pairing mechanism
• Ground state oxygen holes and the metal-insulator transition in the negative charge transfer rare-earth nickelates
• Theory of magnetic excitations in iron-based layered superconductors
• Symmetry of spin excitation spectra in the tetragonal paramagnetic and superconducting phases of 122-ferropnictides
• Antiferromagnetic ordering in the absence of a structural distortion in Ba(Fe{1-x}Mn{x})2As2
• Suppression of superconductivity by Neel-type magnetic fluctuations in the iron pnictides
• Competition between stripe and checkerboard magnetic instabilities in Mn-doped BaFe2As2
• Enhancing magnetic stripe order in iron pnictides by RKKY exchange interactions
• Crossover from Collective to Incoherent Spin Excitations in Superconducting Cuprates Probed by Detuned Resonant Inelastic X-ray Scattering
• Spin and Orbital Characters of Excitations in Iron Arsenide Superconductors Revealed by Simulated Fe L-Edge RIXS
• Intra-layer doping effects on the high-energy magnetic correlations in NaFeAs
• Local and collective magnetism of EuFe${}_2$As${}_2$
• Presence of magnetic excitations in SmFeAsO
• Possible unconventional superconductivity in substituted BaFe${}_2$As${}_2$ revealed by magnetic pair-breaking studies

Cited by in corpus (10)

• Evolution of spin excitations from bulk to monolayer FeSe
• Spin-excitation anisotropy in the nematic state of detwinned FeSe
• Description of resonant inelastic x-ray scattering in correlated metals
• Reciprocity between local moments and collective magnetic excitations in the phase diagram of BaFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$
• Orbital localization and the role of the Fe and As $4p$ orbitals in BaFe${}_2$As${}_2$ probed by XANES
• Incoherent electronic band states in Mn-substituted BaFe${}_2$As${}_2$
• Spin dynamics in NaFeAs and NaFe${}_{0.53}$Cu${}_{0.47}$As probed by resonant inelastic X-ray scattering
• Hole doping and electronic correlations in Cr-substituted BaFe${}_2$As${}_2$
• Coexistence of insulator-like paramagnon and metallic spin-orbit exciton modes in SrIrO${}_3$
• Crystal growth and characterization of a hole-doped iron-based superconductor Ba(Fe${}_{0.875}$Ti${}_{0.125}$)${}_2$As${}_2$