Related papers: Electronic phase separation in the slightly underd…
We use neutron scattering to study the structural and magnetic phase transitions in the iron pnictides CeFeAsO1-xFx as the system is tuned from a semimetal to a high-transition-temperature (high-Tc) superconductor through Fluorine (F)…
We carried out combined transport and optical measurements for BaFe2As2 and five isostructural transition-metal (TM) pnictides. The low-energy optical conductivity spectra of these compounds are, to a good approximation, decomposed into a…
A theory of superconductivity in the iron-based materials requires an understanding of the phase diagram of the normal state. In these compounds, superconductivity emerges when stripe spin density wave (SDW) order is suppressed by doping,…
The charge distribution in RFeAsO$_{1-x}$F$_x$ (R=La, Sm) iron pnictides is probed using As nuclear quadrupole resonance. Whereas undoped and optimally-doped or overdoped compounds feature a single charge environment, two charge…
We report powder and single crystal neutron diffraction measurements of the magnetic order in AMnBi2 (A = Sr and Ca), two layered manganese pnictides with anisotropic Dirac fermions on a Bi square net. Both materials are found to order at…
Combined neutron and x-ray diffraction experiments demonstrate the formation of a low-temperature minority tetragonal phase in Ba$_{0.76}$K$_{0.24}$Fe$_2$As$_2$ in addition to the majority magnetic, orthorhombic phase. A coincident…
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…
We demonstrate that magnetic phase separation and competing spin order in the colossal magnetoresistive (CMR) manganites can be directly explored via tuning strain in bulk samples of nanocrystalline La$_{1-x}$Ca$_x$MnO$_3$. Our results show…
We present a detailed investigation of the magnetic and superconducting properties of Ca1-xNaxFe2As2 single crystals with x = 0.00, 0.35, 0.50, and 0.67 by means of the local probe techniques Moessbauer spectroscopy and muon spin relaxation…
The electronic structure, magnetic and structural properties of the superconductor ThFeAsN are discussed in relation to the Fe-pnictide and Fe-chalcogenide superconductors based on results of first principles calculations. The electronic…
We studied phase separation in a single-crystalline antiferromagnetic superconductor Rb2Fe4Se5 (RFS) using a combination of scattering-type scanning near-field optical microscopy (s-SNOM) and low-energy muon spin rotation (LE-\mu SR). We…
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 $s^+$…
BaFe2As2 (Ba-122) and (Ba0.6K0.4)Fe2As2 (K-doped Ba-122) powders were successfully synthesized from the elements using a reaction method, which incorporates a mechanochemical reaction using high-impact ball milling. Mechanically-activated,…
High-pressure magnetization, structural and 57Fe M\"ossbauer studies were performed on superconducting Rb0.8Fe1.6Se2.0 with Tc = 32.4 K. The superconducting transition temperature gradually decreases on increasing pressure up to 5.0 GPa…
We present temperature dependent magnetic neutron diffraction measurements on Ba(Fe$_{1-x}$Co$_{x}$)$_{2}$As$_{2}$ for $x$ = 0.039, 0.022, and 0.021 as-grown single crystals. Our investigations probe the behavior near the magnetic…
The relationship between vacancy ordering and magnetism in TlFe1.6Se2 has been investigated via single crystal neutron diffraction, nuclear forward scattering, and transmission electron microscopy. The examination of chemically and…
We discuss the novel superconducting characteristics and unusual normal-state properties of iron (Fe)-based pnictide superconductors REFeAsO$_{1-y}$ (RE=La,Pr,Nd) and Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$($T_{c}=$ 38 K) by means of $^{57}$Fe-NMR…
We present a systematic investigation of the antiferromagnetic ordering and structural distortion for the series of Ba(Fe{1-x}Ru{x})2As2 compounds (0 <= x <= 0.246). Neutron and x-ray diffraction measurements demonstrate that, unlike for…
We report a high resolution neutron diffraction investigation of the coupling of structural and magnetic transitions in Ba1xKxFe2As2. The tetragonal-orthorhombic and antiferromagnetic transitions are suppressed with potassium-doping,…
A theory that fully describes previously observed neutron Bragg spots indicative of magnetic order in the pseudo-gap phase of YBa2Cu3O6 + x is presented. Magnetic diffraction intensities, unveiled by polarization analysis, are explained by…