Related papers: Nanoscale Interlayer Defects in Iron Arsenides
The chromium arsenides BaCr2As2 and BaCrFeAs2 with ThCr2Si2 type structure (space group I4/mmm; also adopted by '122' iron arsenide superconductors) have been suggested as mother compounds for possible new superconductors. DFT-based…
BaFe2As2 exhibits properties characteristic of the parent compounds of the newly discovered iron (Fe)-based high-TC superconductors. By combining the real space imaging of scanning tunneling microscopy/spectroscopy (STM/S) with momentum…
Controlling mesoscale and nanoscale material structures and properties through self-organized atomic behavior is essential for atomic-scale manufacturing. However, direct and visual studies on the cross-scale effects of such atomic…
This study investigates the changes of magnetic ordering temperature via nano- and mesoscale structural features in an iron arsenide. Although magnetic ground states in quantum materials can be theoretically predicted from known crystal…
In iron-based superconductors, a unique tri-layer Fe-As (Se, Te, P) plays an essential role in controlling the electronic properties, especially the Cooper pairing interaction. Here we use scanning tunneling microscopy/spectroscopy (STM/S)…
Two iron-chalcogenide superconductors Li(x)[C5H5N](y)Fe(2-z)Se2 and Cs(x)Fe(2-z)Se2 in the as-prepared and annealed state have been investigated by means of the Moessbauer spectroscopy versus temperature. Multi-component spectra are…
The recent discovery of high temperature superconductivity in a layered iron arsenide has led to an intensive search to optimize the superconducting properties of iron-based superconductors by changing the chemical composition of the spacer…
A new iron-based superconductor (Ca,Pr)FeAs2 was discovered. Plate-like crystals of the new phase were obtained and crystal structure was investigated by single-crystal X-ray diffraction analysis. The structure was identified as the…
Polycrystalline samples of the layered iron arsenides Sr2CrO3FeAs and Ba2ScO3FeAs were synthesized by high temperature solid state reactions and their crystal structures determined by the X-ray powder diffraction. Their structures are…
In high temperature cuprate superconductors, the interlayer coupling between the CuO$_2$ planes plays an important role in dictating superconductivity, as indicated by the sensitive dependence of the critical temperature (T$_C$) on the…
We investigate the chemical substitution of group 5 into BaFe2As2 (122) iron arsenide, in the effort to understand why Fe-site hole doping of this compound (e.g., using group 5 or 6) does not yield bulk superconductivity. We find an…
Recent finding of an {\it unusual} in-plane resistivity anisotropy in the underdoped 122-family at high temperature ($T$) suggests an orbital nematic (ON) order, posing a challenge to extant theories. The {\it sign} of the anisotropy…
We have discovered first homologous series of iron pnictide oxide superconductors (Fe2As2)(Can+1(Sc,Ti)nOy) [n = 3,4,5]. These compounds have extremely thick blocking layers up to quintuple perovskite oxide layers sandwiched by the Fe2As2…
In BaFe2As2, structural and magnetic planar defects begin to proliferate below the structural phase transition, affecting descriptions of magnetism and superconductivity. We study using density-functional theory the stability and magnetic…
Superconductivity with exotic properties has often been discovered in materials with a layered (two-dimensional) crystal structure. The low dimensionality affects the electronic structure of materials, which could realize a high transition…
We report scanning tunneling microscopy studies of the local structural and electronic properties of the iron selenide superconductor K0.73Fe1.67Se2 with TC = 32K. On the atomically resolved FeSe surface, we observe well-defined…
Engineering unconventional superconductors is a central challenge in condensed matter physics. Molecule-intercalated TaS2 superlattices have recently been reported to host such states, yet their origin remains debated, underscoring the…
We synthesized new layered iron arsenide oxides (Fe2As2)(Sr4(Sc,Ti)3O8),(Fe2As2)(Ba4Sc3O7.5), and (Fe2As2)(Ba3Sc2O5). The crystal structures of these compounds are tetragonal with a space group of I4/mmm. The structure of…
We report the unprecedented square-planar coordination of iridium in the iron iridium arsenide Ca10(Ir4As8)(Fe2As2)5. This material experiences superconductivity at 16 K. X-ray photoemission spectroscopy and first- principles band…
The Fe-vacancy ordering patterns in the superconducting KxFe2-ySe2 and non-superconducting Kx(Fe,Co)2-ySe2 samples have been investigated by electron diffraction and high angle annular dark field scanning transmission electron microscopy.…