Superconducting NbC nanoparticles synthesized by laser ablation in a liquid.

Niobium carbide (NbC) is a high-field type II superconductor with a critical temperature () of 11.1 K, slightly exceeding that of pure Nb ( = 9 K). The reduction of NbC to the nanoparticle scale leads to significant changes in its critical field and/or the superconducting temperature.

Synthesis, characterization, and incorporation of upconverting nanoparticles into a dental adhesive.

The purpose of this study was to describe the synthesis, characterization, and functionalization of b-NaYF4:30%Yb/0.5%Tm upconverting nanocrystals for use as nanofillers in a dental adhesive and microscopically evaluate the interface between the particles and a commercial adhesive. The upconverting nanoparticles were synthesized and purified by thermal decomposition, and their chemical composition determined by energy dispersive X-Ray spectroscopy.

Controlling the thermal switching in upconverting nanoparticles through surface chemistry.

Photon upconversion taking place in small rare-earth-doped nanoparticles has been recently observed to be thermally modulated in an anomalous manner, showing thermal enhancement of the emission intensity. This effect was proved to be linked to the role of adsorbed water molecules as surface quenchers. The surface capping of the particles has a direct influence on the thermal dynamics of water adsorption and desorption, and therefore on the optical properties.

Collective phase-like mode and the role of lattice distortions at TN ~TC in RMn2O5 (R= Pr, Sm, Gd, Tb, Bi).

We report on electronic collective excitations in RMn(2)O(5) (R =Pr, Sm, Gd, Tb) showing condensation starting at and below ~T(N) ~T(C)~ 40-50 K. Their origin is understood as partial delocalized e(g) electron orbitals in the Jahn-Teller distortion of the pyramid dimer with strong hybridized Mn(3+)-O bonds. Our local probes, Raman, infrared, and x-ray absorption, back the conclusion that there is no structural phase transition at T(N)~T(C).