相关论文: Magnetic ordering in mackinawite (tetragonal FeS):…
High resolution angle-resolved photoemission measurements have been carried out on BaFe2As2, a parent compound of the FeAs-based superconductors. In the magnetic ordering state, there is no gap opening observed on the Fermi surface.…
We present the magnetic structure of the itinerant monoarsenide, FeAs, with the B31 structure. Powder neutron diffraction confirms incommensurate modulated magnetism with wavevector $\mathbf{q} = (0.395\pm0.001)\mathbf{c}^*$ at 4 K, but…
A direct and element-specific measurement of the local Fe spin moment has been provided by analyzing the Fe 3s core level photoemission spectra in the parent and optimally doped CeFeAsO1-xFx (x = 0, 0.11) and Sr(Fe1 xCox)2As2 (x = 0, 0.10)…
Here we present a combined study of the slightly underdoped novel pnictide superconductor Ba(1-x)K(x)Fe(2)As(2) by means of X-ray powder diffraction, neutron scattering, muon spin rotation (muSR), and magnetic force microscopy (MFM).…
We report density functional calculations of the electronic structure, Fermi surface, phonon spectrum, magnetism and electron-phonon coupling for the superconducting phase FeSe, as well as the related compounds FeS and FeTe. We find that…
Despite of the importance of magnetism in possible relation to other key properties in iron-based superconductors, its understanding is still far from complete especially for FeSe systems. On one hand, the origin of the absence of magnetic…
Nematicity and magnetism are two key features in Fe-based superconductors, and their interplay is one of the most important unsolved problems. In FeSe, the magnetic order is absent below the structural transition temperature $T_{str}=90$K,…
The discovery of the Fe pnictide superconductors generated great interest as the structure consists of planes of a magnetic material quite similar to the cuprate superconductors. Fe(Te0.5Se0.5) is a particularly simple system whose planes…
We consider phase transitions and potential co-existence of spin-density-wave (SDW) magnetic order and extended s-wave ($s^+$) superconducting order within a two-band itinerant model of iron pnictides, in which SDW magnetism and $s^+$…
We use bulk magnetic susceptibility, electronic specific heat, and neutron scattering to study structural and magnetic phase transitions in Fe$_{1+y}$Se% $_x$Te$_{1-x}$. Fe$_{1.068}$Te exhibits a first order phase transition near 67 K with…
We study whether Fermi-surface (FS) nesting can give rise to high-temperature superconductivity in iron pnictides. Starting with ab initio construction of an effective four-orbital model, we employ the fluctuation-exchange approximation to…
By applying density functional theory calculations to iron chalcogenides, we find that magnetic order in Fe$_{1+y}$Te and magnetic instability at $(\pi,\pi)$ in K$_y$Fe$_2$Se$_2$ are controlled by interstitial and interlayer cations,…
Superconductivity in FeSe emerges from a nematic phase that breaks four-fold rotational symmetry in the iron plane. This phase may arise from orbital ordering, spin fluctuations, or hidden magnetic quadrupolar order. Here we use inelastic…
Clarifying the magnetic ground state is essential for analysing unconventional superconductivity, because microscopic magnetic order provides one of the basic starting assumptions for spin-fluctuation pairing theories. FeSe exhibits…
The interplay of superconductivity and magnetism is a subject of ongoing interest, stimulated most recently by the discovery of Fe-based superconductivity and the recognition that spin-fluctuations near a magnetic quantum critical point may…
Magnetic properties of iron chalcogenide superconducting materials are investigated using density functional calculations. We find the stability of magnetic phases is very sensitive to the height of chalcogen species from the Fe plane:…
We use inelastic neutron scattering to show that the spin waves in the iron chalcogenide Fe$_{1.05}$Te display novel dispersion clearly different from those in the related iron pnictide systems. By fitting the spin waves to a Heisenberg…
In the metallic magnet Nb$_{1-y}$Fe$_{2+y}$, the low temperature threshold of ferromagnetism can be investigated by varying the Fe excess $y$ within a narrow homogeneity range. We use elastic neutron scattering to track the evolution of…
We analyze magnetic order in iron-chalcogenide Fe$_{1+y}$Te -- the parent compound of high-temperature superconductor Fe$_{1+y}$Te$_{1-x}$Se$_x$. Neutron scattering experiments show that magnetic order in this material contains components…
CeTe$_3$ is a van der Waals antiferromagnet composed of magnetic [CeTe]$^+$ layers coupled to highly conducting Te$^{0.5-}$ square nets. Its simple quasi-two-dimensional electronic structure and cleavable nature make it an appealing…