Hole doping of cuprate superconductors removes electrons from the antibonding planar Cu3dx2−y2O2pxy states; thus increasing doping is expected to shorten the planar Cu–O bonds. All accessible crystallographic data, however, give evidence for a significant deviation from the Pauling-type contraction of covalent bonds on increasing covalency. Between the onset of superconductivity at nI−M = 0.07(...

Nickel was doped into Li3VO4 (Ni-LVO) successfully via a facile room temperature reaction, and the resulting Ni-LVO nanocrystallites showed excellent lithium-ion storage properties with a capacity of 650 mAh g−1 at 50 mAh g−1 and excellent capacity stability as an anode in lithium-ion batteries, maintaining nearly 100% of the initial reversible capacity after 800 cycles at 1 A g−1. The superior...

A series of substitutional solid solutions-Eu₇Cu44-xTxAs23 (T = Fe, Co, Ni)-based on a recently discovered clathrate-like compound (Eu₇Cu44As23) were synthesized from the elements at 800 °C. Almost up to 50% of Cu can be substituted by Ni, resulting in a linear decrease of the cubic unit cell parameter from a = 16.6707(1) Å for the ternary compound to a = 16.3719(1) Å for the sample with the no...

Hybridization of atomic orbitals in graphene on Ni(111) opens a large energy gap of ≈2.8 eV between non-hybridized states at the K-point. Here we use alkali metal adsorbate to reduce and even eliminate this energy gap, and also identify a mechanism responsible for decoupling graphene from the Ni substrate without intercalation of atomic species underneath graphene. Using angle-resolved photoemi...

Doping of titania nanotubes is one of the efficient way to obtain improved physical and chemical properties. Through electrochemical anodization and annealing treatment, Ni-doped TiO2 nanotube arrays were fabricated and their hydrogen sensing performance was investigated. The nanotube sensor demonstrated a good sensitivity for wide-range detection of both dilute and high-concentration hydrogen ...

Different amounts of Ni-doped TiO(2) (Ni = 0.1 to 10%) powders and thin films were prepared by following a conventional coprecipitation and sol-gel dip coating techniques, respectively, at 400 to 800°C, and were thoroughly characterized by means of XRD, FT-IR, FT-Raman, DRS, UV-visible, BET surface area, zeta potential, flat band potential, and photocurrent measurement techniques. Photocatalyti...

The effects of phosphorus doping on the structural and superconducting phase transitions of BaNi2(As(1-x)P(x))2 were studied. The specific heat, resistivity, and magnetic susceptibility were measured. The results revealed an abrupt increase in the superconducting transition temperature (T(c)) from 0.6 K in the triclinic phase (space group P1¯) with less phosphorus (x≤0.067) to 3.3 K in the tetr...

We report on in situ doping of InAs nanowires grown by metal-organic vapor-phase epitaxy without any catalyst particles. The effects of various dopant precursors (Si(2)H(6), H(2)S, DETe, CBr(4)) on the nanowire morphology and the axial and radial growth rates are investigated to select dopants that enable control of the conductivity in a broad range and that concomitantly lead to favorable nano...