相关论文: Surface functionalization enhanced magnetism in Sn…

We report, for the first time, the luminescence property of the hydroxyl group surface functionalized quantum dots (QDs) and nanoparticles (NPs) of SnO_2 using low energy excitations of 2.54 eV (488 nm) and 2.42 eV (514.5 nm). This…

Magnetite ferrite (Fe3O4) nanoparticles have attracted considerable interest due to their tunable physico-chemical properties and relevance in functional materials. In this work, uncoated Fe3O4 nanoparticles and surface-modified Fe3O4…

The occurence of spin-polarization at ZrO$_{2}$, Al$_{2}$O$_{3}$ and MgO surfaces is proved by means of \textit{ab-initio} calculations within the density functional theory. Large spin moments, as high as 1.56 $\mu_B$, develop at O-ended…

Oxygen vacancies at the SnO2(110) and (101) surface and subsurface sites have been studied in the framework of density functional theory by using both all-electron Gaussian and pseudopotential plane-wave methods. The all-electron…

We use a combination of density functional theory and Monte Carlo calculations to calculate the surface magnetization in magnetoelectric $\mathrm{Cr_2O_3}$ at finite temperatures. Such antiferromagnets, lacking both inversion and…

For large-scale deployment and use of polymer electrolyte fuel cells, high-performance electrocatalysts with low platinum consumption are desirable. One promising strategy to meet this demand is to explore alternative materials that retain…

Metal nanoparticle (NP) surface coatings are known to significantly enhance the ultra-violet luminescence intensity of ZnO. Although there is general agreement that resonantly excited Localized Surface Plasmons (LSPs) in metal NPs can…

The effect of thermal annealing on wurtzite ZnO, terminated by two surfaces, (0 0 0 $\bar 1$) (which is oxygen-terminated) and (0 0 0 1) (which is Zn-terminated), is investigated via molecular dynamics simulation using reactive force field…

We utilize classical molecular dynamics to study surface effects on the piezoelectric properties of ZnO nanowires as calculated under uniaxial loading. An important point to our work is that we have utilized two types of surface treatments,…

Surface doping of ZnO allows for tailoring the surface chemistry of the material while preserving the superb electronic structure of the bulk. Apart from obvious changes in adsorption energies and activation energies for catalysis, surface…

In the majority of magnetic systems the surface is required to order at the same temperature as the bulk. In the present study, we report a distinct and unexpected surface magnetic phase transition, uniquely at a lower temperature than the…

Within a rather general tight-binding framework, we studied the magnetic properties of Ni$_{n}$ clusters with $n=9$ through 60. In addition to usual hopping, exchange, and spin-orbit coupling terms, our Hamiltonian also included orbital…

We present a microscopic model for nanoparticles, of the maghemite ($\gamma $% -Fe$_{2}$O$_{3}$) type, and perform classical Monte Carlo simulations of their magnetic properties. On account of M\"{o}ssbauer spectroscopy and high-field…

Two-dimensional (2D) materials showing room-temperature magnetism and high coercivity are desired for combining magnetism with semiconducting properties useful for spintronics. In this work, the magnetic properties of the 1T phase of…

Ultraviolet-ozone (UV-O3) treatment is a simple but effective technique for surface cleaning, surface sterilization, doping and oxidation, and is applicable to a wide range of materials. In this study, we investigated how UV-O3 treatment…

Effect of ambient gases on photoluminescence (PL) and electrical conductivity of films prepared using ZnO nanoparticles (NPs) have been investigated. It is observed that NPs of size below 20 nm kept inside a chamber exhibit complete…

Quantum spin magnetometry using optically pumped $^{199}$Hg has been successfully used in many fundamental physics experiments. A serious problem that has not been resolved is the instability of the $^{199}$Hg spin relaxation rate in atomic…

We report on magnetic measurements as a function of field, temperature and time (relaxation) in superconducting Nb films of critical temperature Tc = 9.25 K. The magnetic measurements as a function of field exhibited a second magnetization…

ZnO nanoparticles (NP) of size less than around 20 nm inside a chamber exhibits complete reduction in their visible photoluminescence (PL) intensity when partial pressure of oxygen in the surrounding gaseous environment is decreased by…

We present the results of Monte Carlo simulations of the magnetic properties of individual spherical nanoparticles with the aim to explain the role played by surface anisotropy on their low temperature magnetization processes. Phase…