This review paper summarizes our very recent works on the synthesis of multifunctional transparent nanocomposite thin films or coatings based on metal atom clusters by an electrophoretic deposition (EPD) process. Eight different octahedral atom clusters with niobium, molybdenum or tantalum as metallic cores were used to prepare highly transparent thin films in the visible. Green, yellow, orange, red and brown colored films were successfully fabricated by coating on a transparent conductive oxide glass substrate. Transparent nanocomposite films with prominent luminescent properties were obtained by using Mo6 clusters whereas ultra-violet (UV) and near infrared (NIR) filters were realized by using Nb6 or Ta6 clusters. The EPD process appears to be a new strategy to fabricate highly transparent, homogeneous and colored nanocomposite thin films and coatings for smart windows and solar technologies in a very short time (<90 s).

Heteroepitaxial VO2 thin films on GaN: Structure and metal-insulator transition characteristics J. Appl. Phys. 112, 074114 (2012) Investigation of nonuniformity phenomenon in nanoscale SiO2 and high-k gate dielectrics J. Appl. Phys. 112, 064119 (2012) Strain dependent stabilization of metallic paramagnetic state in epitaxial NdNiO3 thin films Appl. Phys. Lett. 101, 132101 (2012) Electrical and optical properties of vanadium dioxide containing gold nanoparticles deposited by pulsed laser deposition Appl.Resistive switching in binary metal oxides consists of conductivity changes originating from the electrical creation/dissolution of conductive filaments (CFs) at nanoscale. The investigation of CF local properties can only be achieved through physical and electrical studies at the scale of 10 nm or less, that is, the characteristic size of CFs. This work reports on the direct manipulation of individual CFs formed through insulating NiO films by conductive atomic force microscopy (CAFM) and the comparison between forming/reset processes induced by CAFM and those observed in large-area devices with the same NiO film. The switching variability due to local defects, such as grain boundaries and dislocations, is directly evidenced by CAFM during electroforming process. Our results also indicate that the forming voltage under CAFM can be significantly smaller than the one observed in large-area devices, thus providing evidence for the electric-field enhancement underneath the CAFM tip. Filament deactivation, or reset, at extremely low currents close to 100 nA is demonstrated and described in terms of electrode-limited CF. These results suggest that device engineering and CF size limitation may allow for a significant reduction of forming voltage and reset current in resistive switching random-access memory switching. V C 2012 American Institute of Physics. [http://dx.

Periodic arrays of anisotropic silver nanoparticles having peculiar optical properties are fabricated at a macroscopic scale. The proposed scalable method is based on temperature-assisted solid-state dewetting of a continuous thin layer deposited on a silica substrate patterned by the nano imprint technique. The resulting nanoparticles are shaped like diamonds and are half-embedded into the patterned silica. A period-dependent optimum in film thickness for the quality of spatial organization is found and discussed in terms of thermodynamics and, for the first time, in terms of the role of grains in the dewetting process. The optical properties of the arrays are driven by not only simply the particle shape but also the lattice period and the degree of order. A surface lattice resonance that disperses with the underlying period is evidenced experimentally and confirmed by optical simulations. The opportunity to fabricate and tune such an assembly of plasmonic particles on transparent substrate opens interesting perspectives for not only fundamental photonics but also potential optical applications.