Related papers: Tuning of CeO$_2$ buffer layers for coated superco…
First principles band-structure calculations for large supercells of Ba$_{2}$CuO$_{4-\delta}$ and La$_{2}$CuO$_{4-\delta}$ with different distributions and concentrations of oxygen vacancies show that the effective doping on copper sites…
Doping of La_2CuO_4 and La_{1.6}Nd_{0.4}CuO_4 with Sr gives rise to holes that locate pairwise at lattice-site O atoms. Such O atoms reside as lattice defects in the CuO_2 planes if the doping level x is below a watershed value, x < x^, but…
A series of layered CeO$_{1-x}$F$_x$FeAs compounds with x=0 to 0.20 are synthesized by solid state reaction method. Similar to the LaOFeAs, the pure CeOFeAs shows a strong resistivity anomaly near 145 K, which was ascribed to the…
Since the early days of the discovery of hole doped high-Tc cuprates, the variation of the oxygen isotope exponent (IE) with the number of doped holes, p, in the CuO2 planes has been a source of considerable debate. There is a growing…
Layer-by-layer oxide molecular beam epitaxy has been used to synthesize cuprate-nickelate multilayer structures of composition (La$_2$CuO$_4$)$_m$/LaO/(LaNiO$_3$)$_n$. In a combined experimental and theoretical study, we show that these…
The Seebeck coefficient $S$ of the cuprate superconductor La$ _{2-x} $Sr$_{x} $CuO$ _{4}$ (LSCO) was measured in magnetic fields large enough to access the normal state at low temperatures, for a range of Sr concentrations from $x = 0.07$…
In the iron-based high-Tc bulk superconductors, Tc above 50K was only observed in the electron-doped 1111-type compounds. Here we revisit the electron-doped SmFeAsO polycrystals to make a further investigation for the highest T-c in these…
The techniques of growing films with different parameters in single process make it possible to build up a sample library promptly. In this work, with a precisely controlled moving mask, we synthetized superconducting…
It is noteworthy that chemical substitution of BaFe2As2 (122) with the noble elements Cu and Au gives superconductivity with a maximum Tc=3 K, while Ag substitution (Ag-122) stays antiferromagnetic. For Ba(Fe1-xTMx)2As2, TM= Cu, Au, or Ag,…
We theoretically investigate inhomogeneity effects on the charges, electric field gradients and site-projected densities of states in HgBa$_2$CuO$_{4+\delta}$. We find pronounced differences in the doping-induced number of holes at…
We report the antimony (Sb) doping effect in a prototype system of iron-based supercon-ductors LaFeAsO1-yFy (y=0, 0.1, 0.15). X-ray powder diffraction indicates that the lattice pa-rameters increase with Sb content within the doping limit.…
In the cuprate superconductor $YBa_2Cu_3O_{6+x}$, hole doping in the $CuO_2$ layers is controlled by both oxygen content and the degree of oxygen-ordering. At the composition $\rm YBa_2Cu_3O_{6.35}$, the ordering can occur at room…
In this paper we investigate the effect of Cd doping at ultra-low concentrations in SnO$_2$ both experimentally, by measuring the temperature dependence of the electric quadrupole hyperfine interactions with time-differential perturbed…
The contribution of $O^{2-}$ ions to antiferromagnetism in $La_{2-x}Ae_xCuO_4$ ($Ae = Sr, Ba)$ is highly sensitive to doped holes. In contrast, the contribution of $Cu^{2+}$ ions to antiferromagnetism in $Nd_{2-x}Ce_xCuO_{4+y}$ is much less…
By considering both the average structural parameters obtained from Rietveld refinement of neutron powder diffraction data, and the local structural parameters obtained from the atomic pair distribution function, we have tested the recent…
In this work, the electronic and optical properties of a Nitrogen (N) or a Boron (B) doped BeO monolayer are investigated in the framework of density functional theory. It is known that the band gap of a BeO monolayer is large leading to…
The parent compounds of the copper oxide high-Tc superconductors are unusual insulators. Superconductivity arises when they are properly doped away from stoichiometry1. In Bi2Sr2CaCu2O8+x, superconductivity results from doping with excess…
Coupling among conduction electrons (e.g. Zhang-Rice singlet) are often manifested in the core level spectra of exotic materials such as cuprate superconductors, manganites, etc. These states are believed to play key roles in the ground…
We report neutron scattering measurements of the structure and magnetism of stage-4 La_2CuO_{4+y} with T_c ~42 K. Our diffraction results on a single crystal sample demonstrate that the excess oxygen dopants form a three-dimensional ordered…
Recently, the solid-state frustrated Lewis pairs (FLPs) on the surface of CeO2 have been demonstrated to effectively catalyze the selective hydrogenation of unsaturated substrates, hence, the relationship between their intrinsic properties…