Acoustic lattice instabilities at the magneto-structural transition in Fe${}_{1.057(7)}$Te

Abstract

Fe${}_{1.057(7)}$Te undergoes a first-order tetragonal to monoclinc structural transition at T${}_S\sim 70$ K, breaking the C${}_4$ lattice symmetry and simultaneously breaking time reversal symmetry with bicollinear magnetic order. We investigate the soft acoustic lattice dynamics near this combined magneto-structural transition. We apply spherically neutron polarimetry to study the static magnetism near this transition, characterized with x-ray powder diffraction, and find no evidence of static incommensurate magnetic correlations near the onset of monoclinic and bicollinear antiferromagnetic order. This fixes the position of our single crystal sample in the Fe${}_{1+x}$Te phase diagram in the magnetic bicollinear region and illustrates that our sample statically undergoes a transition from a paramagnetic phase to a low-temperature bicollinear phase. We then apply neutron spectroscopy to study the acoustic phonons, related to elastic deformations of the lattice. We find a temperature dependent soft acoustic branch for phonons propagating along [010] and polarized along [100]. The slope of this acoustic phonon branch is sensitive to the elastic constant $C_{66}$ and the shear modulus. The temperature dependence of this branch displays a softening with a minimum near the magneto-structural transition of T${}_S$ $\sim$ 70 K and a recovery within the magnetically ordered low temperature phase. Soft acoustic instabilities are present in the collinear phases of the chalcogenides Fe${}_{1+x}$Te where nematic order found in Fe${}_{1+\delta }$Se is absent. We speculate, based on localized single-ion magnetism, that the relative energy scale of magnetic spin-orbital coupling on the Fe${}^{2+}$ transition metal ion is important for the presence of a nematicity in the chalcogenides.

arXiv comment(13 pages, 10 figures, to be published in Physical Review B)

References in corpus (73)

• The Puzzle of High Temperature Superconductivity in Layered Iron Pnictides and Chalcogenides
• High-temperature superconductivity in iron-based materials
• Nematic order in iron superconductors - who is in the driver's seat?
• Near-degeneracy of several pairing channels in multiorbital models for the Fe-pnictides
• Density functional study of FeS, FeSe and FeTe: Electronic structure, magnetism, phonons and superconductivity
• Antiferromagnetic order and spin dynamics in iron-based superconductors
• To What Extent Iron-Pnictide New Superconductors Have Been Clarified: A Progress Report
• Nematic Fermi Fluids in Condensed Matter Physics
• Extreme Sensitivity of Superconductivity to Stoichiometry in FeSe (Fe1+dSe)
• Incommensurate magnetic order in the alpha-Fe(Te,Se) superconductor systems
• First-order magnetic and structural phase transitions in Fe${}_{1+y}$Se${}_x$Te${}_{1-x}$
• Magnetism and its microscopic origin in iron-based high-temperature superconductors
• The Structural Phase Transition in FeSe (Fe1+dSe)
• A minimal two-band model for the superconducting Fe-pnictides
• Bulk Superconductivity at 14 K in Single Crystals of Fe1+yTexSe1-x
• Anomalous suppression of the orthorhombic distortion in superconducting Ba[Fe(1-x)Cox]2As2
• Orbital-driven nematicity in FeSe
• Emergence of the nematic electronic state in FeSe
• Ubiquitous signatures of nematic quantum criticality in optimally doped Fe-based superconductors
• Magnetism in Fe-based superconductors
• Ironing out the details of unconventional superconductivity
• Origin of the spin density wave instability in AFe${}_2$As${}_2$ (A=Ba, Sr) as revealed by optical spectroscopy
• Superconductivity in S-substituted FeTe
• Lifting of xz/yz orbital degeneracy at the structural transition in detwinned FeSe
• Three orbital model for the iron-based superconductors
• Electronic properties of single-crystalline Fe${}_{1.05}$Te and Fe${}_{1.03}$Se${}_{0.30}$Te${}_{0.70}$
• Superconductivity-induced reentrance of orthorhombic distortion in Ba1-xKxFe2As2
• Manifestations of nematic degrees of freedom in the magnetic, elastic, and superconducting properties of the iron pnictides
• Fe-based superconductors: seven years later
• Magnetic-crystallographic phase diagram of superconducting parent compound Fe${}_{1+x}$Te
• Nematicity as a probe of superconducting pairing in iron-based superconductors
• Orbital Selectivity in Hund's metals: The Iron Chalcogenides
• Interplay between magnetism and superconductivity in iron-chalcogenide superconductors: crystal growth and characterizations
• Tuning the superconducting and magnetic properties in Fe_ySe_0.25Te_0.75 by varying the Fe-content
• Spin fluctuations in iron pnictides and chalcogenides: From antiferromagnetism to superconductivity
• Kinetic Magnetism and Orbital Order in Iron Telluride
• Low-temperature phase diagram of Fe1+yTe
• The intercalation chemistry of layered iron chalcogenide superconductors
• Momentum Dependence of the Nematic Order Parameter in Iron-Based Superconductors
• Interstitial Iron Controlled Superconductivity in Fe1+xTe0.7Se0.3
• Interstitial iron tuning of the spin fluctuations in Fe1+xTe
• First-order structural transition in the magnetically ordered phase of Fe1.13Te
• Continuous magnetic and structural phase transitions in Fe1+yTe
• Magnetic, superconducting, and topological surface states on Fe${}_{1+y}$Te${}_{1-x}$Se${}_x$
• The magnetic and structural properties near the Lifshitz point in Fe1+xTe
• Friedel-like Oscillations from Interstitial Iron in Superconducting Fe1+yTe0.62Se0.38
• Influence of interstitial Fe to the phase diagram of Fe${}_{1+y}$Te${}_{1-x}$Se${}_x$ single crystals
• Ferro-orbital ordering transition in iron telluride Fe${}_{1+y}$Te
• Emergent XY electronic nematicity in iron-based superconductors
• Spin-Orbit Excitons in CoO
• Evidence for short-range magnetic order in the nematic phase of FeSe from anisotropic in-plane magnetostriction and susceptibility measurements
• Competition between commensurate and incommensurate magnetic ordering in Fe(1+y)Te
• Phonon anomalies in FeS
• Soft striped magnetic fluctuations competing with superconductivity in Fe_{1+x}Te
• The magnetic and electronic properties of Oxyselenides - influence of transition metal ions and lanthanides
• Theory of the evolution of magnetic order in Fe${}_{1+y}$Te compounds with increasing interstitial iron
• Spin-Orbital-Intertwined Nematic State in FeSe
• Evidence for anisotropic polar nanoregions in relaxor PMN: A neutron study of the elastic constants and anomalous TA phonon damping
• Spin fluctuations and superconductivity in powders of Fe_1+xTe_0.7Se_0.3 as a function of interstitial iron concentration
• Phonon anomalies in some iron-telluride materials
• Spontaneous orbital polarization in the nematic phase of FeSe
• Nematic correlation length in iron-based superconductors probed by inelastic x-ray scattering
• Manipulating surface magnetic order in iron telluride
• Short-range nematic fluctuations in Sr1-xNaxFe2As2 superconductors
• Solitonic spin-liquid state due to the violation of the Lifshitz condition in Fe${}_{1+y}$Te
• Competing spin density wave, collinear, and helical magnetism in Fe1+xTe
• Imitation of spin density wave order in Cu${}_3$Nb${}_2$O${}_8$
• Soft elastic constants from phonon spectroscopy in hole-doped Ba${}_{1-x}$(K,Na)${}_x$Fe${}_2$As${}_2$ and Sr${}_{1-x}Na$_x$Fe$_2$As$_2$
• Magnetic surface reconstruction in the van-der-Waals antiferromagnet Fe${}_{1+x}$Te
• Spin-orbital correlations from complex orbital order in MgV${}_2$O${}_4$
• Magnetic orders, excitations, and phase transitions in Fe_1+yTe
• Transverse acoustic phonon anomalies at intermediate wavevectors in MgV${}_2$O${}_4$
• Magnetic Properties Controlled by Interstitial or Interlayer Cations in Iron Chalcogenides