Temperature-dependent interplane resistivity ρc(T ) was measured systematically as a function of transitionmetal substitution in the iron-arsenide superconductors Ba(Fe1−xMx)2As2, M = Ni, Pd, Rh. The data are compared with the behavior found in Ba(Fe1−xCox)2As2, revealing resistive signatures of pseudogap. In all compounds we find resistivity crossover at a characteristic pseudogap temperature ...

The optical properties of twinned single crystals of YBa2(Cu12xNix)3O61y have been determined for a nominally pure system and for Ni concentrations of x50.0075 and 0.014 with oxygen dopings of y50.60 ~underdoped! and 0.95 ~optimal! over a wide frequency range above and below Tc . The optical conductivity of the twinned materials shows a rapid increase in the residual conductivity at low frequen...

NiFe oxyhydroxide materials are highly active electrocatalysts for the oxygen evolution reaction (OER), an important process for carbon-neutral energy storage. Recent spectroscopic and computational studies increasingly support iron as the site of catalytic activity but differ with respect to the relevant iron redox state. A combination of hybrid periodic density functional theory calculations ...

C2H2, C2H4, and C2H6 are important oil-dissolved gases in power transformers. Detection of the composition and content of oil-dissolved gases in transformers is very significant in the diagnosis and assessment of the state of transformer operations. The commonly used oil-gas analysis methods have many disadvantages, so this paper proposes a Ni-doped carbon nanotube (Ni-CNT) gas sensor to effect...

A low-resistance ohmic contact to Mg-doped p-type GaN grown by metal-organic chemical vapor deposition (MOCVD) with a carrier concentration of 2 · 10 cm 3 using Pd/Ni/Au metallization was formed. An anneal at 500 C for 1 min in a flowing N2 ambient produced an excellent ohmic contact with a specific contact resistivity as low as 2.4 · 10 5 X cm. X-ray photoelectron spectroscopy (XPS) and Auger ...

The microwave absorption properties of Ni/(C, silicides) nanocapsules prepared by an arc discharge method have been studied. The composition and the microstructure of the Ni/(C, silicides) nanocapsules were determined by means of X-ray diffraction, X-ray photoelectric spectroscopy, and transmission electron microscope observations. Silicides, in the forms of SiOx and SiC, mainly exist in the sh...

The electrochemical analysis of tetracycline was investigated using nickel-implanted boron-doped diamond thin film electrode by cyclic voltammetry and amperometry with a flow injection system. Cyclic voltammetry was used to study the electrochemical oxidation of tetracycline. Comparison experiments were carried out using as-deposited boron-doped diamond thin film electrode (BDD). Nickel-implant...

Doping CeO2 with Pd atoms has been associated with catalytic CO oxidation, but current surface models do not allow CO adsorption. Here, we report a new structure of Pd-doped CeO2(111), in which Pd adopts a square planar configuration instead of the previously assumed octahedral configuration. Oxygen removal from this doped structure is favorable. The resulting defective Pd-doped CeO2 surface is...

The planar oxygen isotope effect coefficient measured as a function of hole doping in the Prand La-doped YBa2Cu3O7 (YBCO) and the Ni-doped La1.85Sr0.15CuO4 (LSCO) superconductors quantitatively and qualitatively follows the form originally proposed by Kresin andWolf [Phys. Rev. B 49, 3652 (1994)], which was derived for polarons perpendicular to the superconducting planes. Interestingly, the inv...

Calcium doped nickel ferrite powders have been prepared by sol-gel combustion technique. Metal nitrates, such as calcium nitrate, nickel nitrate and ferric nitrate, were used as the source materials and citric acid and polyvinyl alcohol were used as the burning agent and agglomeration reducing agent, respectively. The average crystallite size of the prepared ferrite was in the order of ~70- 92 ...