3d transition impurities in wide-gap oxides may function as donor/acceptor defects to modify carrier concentrations, and as magnetic elements to induce collective magnetism. Previous first-principles calculations have been crippled by the LDA error, where the occupation of the 3d-induced levels is incorrect due to spurious charge spilling into the misrepresented host conduction band, and have o...

0008-6223/$ see front matter 2013 Elsevi http://dx.doi.org/10.1016/j.carbon.2013.04.065 * Corresponding author: Fax: +86 025 5209060 E-mail address: [email protected] (Z.H. Ni We present systematical Raman studies of nitrogen doped graphene (NG). Defective graphene by Ar ion bombardment was also studied for comparison. It was found that the defects/nitrogen dopants in NG are not homogenous. Our r...

The influence of different boron precursor powders on the critical current density of MgB2 superconductor with added Ni-Co-B nanoparticles is investigated. Different types of boron have different morphologies, particle sizes and impurity content, all of which have a strong impact on the critical current density ( Jc). The boron samples investigated in this study include three different boron po...

Ni–Mn–In magnetic shape memory alloys, which can be stimulated by an external field, exhibit a fast response and have aroused wide attention in the field of electro-mechanical actuators. However, low working temperature inherent brittleness severely limit their application scenarios. Here, effective strategy is proposed to improve magnetic-field-induced mechanical properties alloys. We predict ...

The crystal structure of MoS$_2$ with strong covalent bonds in plane and weak Van der Waals interactions out gives rise to interesting properties for applications such as solid lubrication, optoelectronics, catalysis, which can be enhanced by transition-metal doping. However, the mechanisms improvement even doped material unclear, we address theoretical calculations. Building on our previous wo...

• The study evaluated Ni- and Co-doping within IrO 2 on the oxygen evolution reaction. Multiple reaction pathways characterized using Density Functional Theory. Ni Co dopants alter thermodynamics kinetics of steps. Theory experiments show lower activation energy. rate determining step was from theory experiments. effect doping structure (OER) studied integrated (DFT) calculations that metal dop...

Ni doped ZnO (Zn1 xNixO) thin films were grown on quartz substrates via magnetron sputtering deposition process with the Ni concentrations of 5, 10 and 20 at.% in the films. The effects of Ni doping level and post annealing on the structural and magnetic properties of Zn1 xNixO films were investigated by means of X-ray diffraction (XRD), alternating gradient magnetometer (AGM) and photoluminesc...

We report the realization of superconductivity by an isovalent doping with phosphorus in LaFeAsO. X-ray diffraction shows that, with the partial substitution of P for As, the Fe2As2 layers are squeezed while the La2O2 layers are stretched along the c-axis. Electrical resistance and magnetization measurements show emergence of bulk superconductivity at ∼10 K for the optimally-doped LaFeAs1−xPxO ...

Synchrotron radiation-based x-ray photoemission spectroscopy was used to study the surface Fermi level position within the band gap for thin metal overlayers of Au, Al, Ni, Ti, Pt, and Pd on n–GaN and p–GaN. Nonequilibrium effects were taken into account by measuring the Fermi edge of the metal overlayer. There are two different behaviors observed for the six metals studied. For Au, Ti, and Pt,...