Related papers: Electronic properties of 3d transitional metal pni…
ThCr2Si2-type Ru-based superconductors LaRu2P2 and LaRu2As2 with Tc ~ 4 K and 7.8 K respectively have been reported very recently. Using the first principles method we investigate the details physical and superconducting properties…
We studied the effect of hydrostatic pressure (P) on the structural phase transitions and superconductivity in the ternary and pseudo-ternary iron arsenides CaFe2As2, BaFe2As2, and (Ba0.55K0.45)Fe2As2, by means of measurements of electrical…
The magnetic structure of superconducting Eu(Fe0.82Co0.18)2As2 is unambiguously determined by single-crystal neutron diffraction. A long-range ferromagnetic order of the Eu2+ moments along the c-direction is revealed below the magnetic…
We report detailed measurements of temperature dependence and ab initio lattice dynamical calculations of the phonon density-of-states of two Sr based iron pnictide parent compounds; SrFe2As2 and SrFeAsF. Although both compounds undergo a…
We report that intrinsic transport and magnetic properties, and their anisotropy from high quality single crystal $CaFe_2As_2$. The resistivity anisotropy ($\rho_c/\rho_{ab}$) is $\sim 50 $, and less than 150 of $BaFe_2As_2$, which arises…
We report ultrafast quasiparticle (QP) dynamics and coherent acoustic phonons in undoped CaFe_2As_2 iron pnictide single crystals exhibiting spin-density wave (SDW) and concurrent structural phase transition at temperature TSDW ~ 165 K…
We report the observation of a nonlinear elastoresistivity response for the prototypical underdoped iron pnictide Ba(Fe$_{0.975}$Co$_{0.025}$)$_2$As$_2$. Our measurements reveal a large quadratic term in the isotropic ($A_{1g}$) electronic…
We use angle-resolved photoemission to study the three dimensional (3D) electronic structure of Co pnictides ACo2As2 with A=Ba, Sr, Ca or a mixture of Sr and Ca. These compounds are isostructural to Fe based superconductors, but have one…
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…
Sr2Cr3As2O2 is composed of alternating square-lattice CrO2 and Cr2As2 stacking layers, where CrO2 is isostructural to the CuO2 building-block of cuprate high-Tc superconductors and Cr2As2 to Fe2As2 of Fe-based superconductors. Current…
CaFe$_2$As$_2$ has been found to be exceptionally sensitive to the application of hydrostatic pressure and superconductivity has been found to exist in a narrow pressure region that appears to be at the interface between two different phase…
We report the complex dielectric function of high-quality $A\textrm{Fe}_2\textrm{As}_2$, ($A$=Ca, Sr, Ba) single crystals with $T_{\mathrm{N}}\approx150\ \textrm{K}$, $200\ \textrm{K}$, and $138\ \textrm{K}$, respectively, determined by…
We have found a remarkably large response of the transition temperature of CaFe2As2 single crystals grown out of excess FeAs to annealing / quenching temperature. Whereas crystals that are annealed at 400 C exhibit a first order phase…
Polycrystalline samples of underdoped (Ba1-xKx)Fe2As2 (x<=0.4) were synthesized and studied by x-ray powder diffraction, magnetic susceptibility, specific heat and 57Fe-Moessbauer-spectroscopy. The structural phase transition from…
Single crystal neutron and high-energy x-ray diffraction have identified the phase lines corresponding to transitions between the ambient-pressure tetragonal (T), the antiferromagnetic orthorhombic (O) and the non-magnetic collapsed…
We report on isofield magnetization curves obtained as a function of temperature in two single crystals of $Ba_{1-x}K_xFe_2As_2$ with superconducting transition temperature $T_c$=28K and 32.7 K. Results obtained for fields above 20 kOe show…
The Fe-based superconducting KxFe2-ySe2 (0.6 {\leg} x {\leg} 1, 0.2{\leg} y {\leg} 0.4) compounds, unlike the well-known RFe2As2 (R = Ba, Sr, Ca) superconductors, contain complex structural features and notable physical properties, such as…
We present an optical spectroscopy study on P-doped CaFe$_2$As$_2$ which experiences a structural phase transition from tetragonal to collapsed tetragonal (cT) phase near 75 K. The measurement reveals a sudden reduction of low frequency…
The observation of non-bulk superconductivity with an unexpectedly high onset transition temperature Tc up to ~ 49 K in non-superconducting single crystalline CaFe2As2 upon rare-earth doping has raised interesting questions concerning its…
In the iron arsenide compound BaFe2As2, superconductivity can be induced either by a variation of its chemical composition, e.g., by replacing Fe with Co, or by a reduction of the unit-cell volume through the application of hydrostatic…