相关论文: Effects of Li doping on H-diffusion in MgH$_2$: a …
We use a combination of ab initio calculations and statistical mechanics to investigate the substitution of Li+ for Mg2+ in magnesium hydride (MgH2) accompanied by the formation of hydrogen vacancies with positive charge (with respect to…
A lithium-doped magnesium hydride Li$_2$MgH$_{16}$ was recently reported [Y. Sun $et$ $al$., Phys. Rev. Lett. {\bf 123}, 097001 (2019)] to exhibit the highest ever predicted superconducting transition temperature $T_{\rm c}$ under high…
Aliovalent doping in an oxide material introduces modifications in the valence state of the host cation and often leads to tailoring the oxygen content in the lattice. Moreover, if the dopant cation is larger than the host cation, the…
We investigate effects of doping on formation energy and concentration of oxygen vacancies at a metal oxide surface, using MgO (100) as an example. Our approach employs density-functional theory, where the performance of the…
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…
It is well known, both theoretically and experimentally, that alloying MgH$_2$ with transition elements can significantly improve the thermodynamic and kinetic properties for H$_2$ desorption, as well as the H$_2$ intake by Mg bulk. Here we…
The structural, magnetic and transport properties have been studied of Li doped CoV2O4 and FeV2O4. Li doping increases the ferri-magnetic ordering temperature of both the samples but decreases the spin-glass transition temperature of…
The effect of Fe doping in the Mn site on the magnetic, transport and structural properties of polycrystalline La1/2Ca1/2MnO3 was studied. Doping with low Fe concentration (< 10%) strongly affects electrical transport and magnetization.…
Mg2NiH4 is a promising hydrogen storage material with fast (de)hydrogenation kinetics. Its hydrogen desorption enthalpy, however, is too large for practical applications. In this paper we study the effects of transition metal doping by…
The effect of Li substitution for Mg and of Li-C co-substitution on the superconducting properties and crystal structure of MgB2 single crystals has been investigated. It has been found that hole doping with Li decreases the superconducting…
Doped lithium lanthanum zirconium oxide (LLZO) is a promising class of solid electrolytes for lithium-ion batteries due to their good electrochemical stability and compatibility with Li metal anodes. Ionic diffusivity in these ceramics is…
Density functional theory calculations indicate that the incorporation of V into Ti lattice positions of rutile TiO2 leads to magnetic V4+ species, but the extension and sign of the coupling between dopant moments confirm that ferromagnetic…
We have evaluated the successes and failures of the Hubbard-corrected density functional theory (DFT+U) approach to study Mg doping of LiCoO$_2$. We computed the effect of the U parameter on the energetic, geometric and electronic…
To understand the link between doping and electronic properties in high temperature superconductors, we report first-principles calculations on the oxygen doping effect for the single layer cuprate HgBa$_2$CuO$_{4+\delta}$. The doping…
Density functional calculations are carried out to understand and tailor the electrochemical profile diffusivity, band gap and open circuit voltage of transition metal doped olivine phosphate $LiFe_{1-x}M_{x}PO_{4}$ (M = V, Cr, Mn, Co and…
Effects of chemical substitution of the divalent transition metals has been systematically investigated in Mg$_{1-x}M_x$B$_2$ (x=0.03; M=Mn, Fe, Co, Ni and Zn). Substitution of magnetic ions, i.e., Mn$^{2+}$, Fe$^{2+}$, Co$^{2+}$ and…
The kinetics of hydrogen absorption by magnesium bulk is affected by two main activated processes: the dissociation of the H$_2$ molecule and the diffusion of atomic H into the bulk. In order to have fast absorption kinetics both activated…
We study the hydrogen effect on the electronic, magnetic and optical properties of Cu$_2$O in presence of different dopants (Na, Li and Ti). The electronic properties calculations show that hydrogen changes the conductivity of Cu$_2$O from…
We report the preparation of Mg1-xLixB2 compounds. Nearly single phased samples were obtained for x<0.3. The in-plane lattice parameter a decreases with Li doping, while the lattice parameter c does not show obvious change. The…
Recent experimental work has realized a new insulating state of samarium nickelate (SmNiO$_3$), accessible in a reversible manner via high-density electron doping. To elucidate this behavior, we use the first-principles density functional…