Related papers: Strain-activated structural anisotropy in BaFe2As2
Polarized inelastic neutron scattering experiments were performed to study magnetic excitations in the normal and superconducting phases of Co-underdoped BaFe$_2$As$_2$, which exhibits coexistence of antiferromagnetic order and…
Nematicity, defined as broken rotational symmetry, has recently been observed in competing phases proximate to the superconducting phase in the cuprate high temperature superconductors. Similarly, the new iron-based high temperature…
On experimental side, BaFe$_2$As$_2$ without doping has been made superconducting by applying appropriate pressure (2-6 GPa). Here, we use a full-potential linearized augmented plane wave method within the density-functional theory to…
Electrical resistivity measurements of detwinned single crystals of the representative iron arsenide Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$ reveal a dramatic in-plane anisotropy associated with the tetragonal-to-orthorhombic structural transition…
We report neutron scattering measurements of cooperative spin excitations in antiferromagnetically ordered BaFe2As2, the parent phase of an iron pnictide superconductor. The data extend up to ~100meV and show that the spin excitation…
We used temperature-dependent neutron diffraction measurements on FeVO4 to understand the temperature driven anisotropy and observed that the maximum change for a and b lattice parameters in conjunction with a large contraction in angle…
Both cuprates and iron-based superconductors demonstrate nematicity, defined as the spontaneous breaking of rotational symmetry in electron systems. The nematic state can play a role in the high-transition-temperature superconductivity of…
We report neutron scattering measurements on single crystals of BaFe$_{1.92}$Co$_{0.08}$As$_2$. The magnetic Bragg peak intensity is reduced by 6 % upon cooling through T$_C$. The spin dynamics exhibit a gap of 8 meV with anisotropic…
Of all parent compounds of iron-based high-temperature superconductors, EuFe2As2 exhibits by far the largest magnetostructural coupling due to the sizable biquadratic interaction between Eu and Fe moments. While the coupling between Eu…
Using femtosecond time-resolved x-ray diffraction we investigate the structural dynamics of the coherently excited A1g phonon mode in the Fe-pnictide parent compound BaFe2As2. The fluence dependent intensity oscillations of two specific…
The S = 1/2 triangular lattice antiferromagnet (TLAF) is a paradigmatic example of frustrated quantum magnetism. An ongoing challenge involves understanding the influence of exchange anisotropy on the collective behavior within such…
We report inelastic neutron scattering measurements of the spin dynamics in the layered hexagonal magnet 2H-AgNiO2 which has stacked triangular layers of antiferromagnetically-coupled Ni2+ spins (S=1) ordered in a collinear alternating…
By performing high-pressure single-crystal neutron diffraction measurements, the evolution of structure and magnetic ordering in EuFe2As2 under hydrostatic pressure were investigated. Both the tetragonal-toorthorhombic structural transition…
We present results of angle-dependent magnetoresistance measurements and direct optical images of underdoped Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$ which reveal partial detwinning by action of a 14T magnetic field. Driven by a substantial…
We use polarized inelastic neutron scattering to study low-energy spin excitations and their spatial anisotropy in electron-overdoped superconducting BaFe$_{1.85}$Ni$_{0.15}$As$_{2}$ ($T_c=14$ K). In the normal state, the imaginary part of…
We report a Raman scattering study of nematic degrees of freedom in the iron-based superconductor parent compound BaFe$_2$As$_2$ under tunable uniaxial strain. We demonstrate that the polarization resolved arsenic (As) phonon intensity can…
We report inelastic neutron scattering studies of magnetic excitations in antiferromagnetically ordered SrFe$_{2}$As$_{2}$ ($T_{N}=220$ K), the parent compound of the FeAs-based superconductors. At low temperatures (T=7 K), the spectrum of…
We present a single crystal neutron scattering study of BaMn2Bi2, a recently synthesized material with the same ThCr2Si2-type structure found in several Fe-based unconventional superconducting materials. We show long range magnetic order,…
We report the in-plane anisotropy of the Seebeck and Nernst coefficients as well as of the electrical resistivity determined for the series of the strain-detwinned single crystals of Ba(Fe1-xCox)2As2. Two underdoped samples (x = 0.024,…
We report $^{75}$As nuclear magnetic resonance measurements on single crystals of RbFe$_{2}$As$_{2}$ and CsFe$_{2}$As$_{2}$. Taking previously reported results for KFe$_{2}$As$_{2}$ into account, we find that the anisotropic electronic…