${\mathrm{NdNiO}}_{3}$ is studied by electron diffraction and Raman scattering, drastic changes are observed at the metal-insulator transition. These features explained in framework of a charge disproportionation nickel, which variance from earlier results, but consistent with recent studies on smaller rare earth nickelates. The spectra insulator phase discussed respect to elpasolite arrangement. It shown that several frequencies directly probe transfer, leads us conclude this parameter...

Using a "two-steps" synthesis mode, the homogeneity ranges of perovskites Ln1-xBaxMnO3 were extended up to x = 0.60 for Pr-based samples and 0.50 La ones. Two new perovskites, cubic form P-type tetragonal phase (with aC × 2aC parameters) have been isolated. The HREM study shows nanostructural behavior form, only stabilized in small domains. These compounds exhibit ferromagnetic metallic paramagnetic insulating transition at increasing temperature, over large range, independent nature...

Coherent acoustic phonon generation processes on the picosecond time scale were investigated in metal-insulator transition compound ${\text{NdNiO}}_{3}$. Time-resolved optical pump-probe methods employed. While at high temperature thermoelastic process drives photogeneration of phonons, an additional contribution can be identified when to insulating state $T<{T}_{\text{MI}}$ takes place. The latter photogenerated stress is possibly electronic nature (deformation-potential mechanism). We...

A structural and magnetoresistance study of layered manganites with nominal formula Ln2−yA1+yMn2O7 (Ln=Nd, Pr) (A=Ca, Sr, Ba) is presented. combination electron diffraction high resolution microscopy allows us to propose a model where two perovskite blocks are intergrown one rock salt type layer. The average structure crystallizes in tetragonal unit cell lattice parameters a≊b≊ap c≊19.3 Å. Moreover, an orthorhombic distortion the a≊b≊√ap Å has been evidenced for calcium-based oxides....

Considering it is somewhat difficult to crystallize thermochromic nickelates through a soft process, major challenge in NdNiO3 crystallization the stabilization of Ni3+ oxidation state against Ni2+. The aim present work was understand why annealing sufficient while an oxygen high pressure (200 bar) usually considered as required. Thin films 300 nm have been deposited by reactive magnetron sputtering at room temperature and working 0.5, 4, 7 Pa. content as-deposited annealed estimated...

Nd 0.7 Eu 0.3 NiO 3 thin films are deposited by rf sputtering and subsequent oxygen pressure annealing on (100) oriented silicon substrate. We characterize the thermochromic properties of measuring electrical transition, infrared transmittance, reflectance. The effect at room temperature is observed. Resistivity measurements exhibit a sharper hysteresis loop than usually observed in NdNiO3 films. Infrared 8–14 μm wavelength range spectra reveal contrast 30% reflectance 55% transmittance.

We have synthesized (Sm1−x,Cax)MnO3 and related compositions to show their potential use as thermochromic switch in the infrared range. Depending on temperature or composition, single phase is stabilized using polyacrilamide gel process. Infrared transmittance was measured selected samples 1,42–25μm Relative contrast up 0.773 8–14μm Full opacity range occurs at temperatures between 273 300K, depending composition. The application of perovskites manganites coating discussed.

Visible ultrafast optical property studies have been performed in the metal-insulator transition compound $\mathrm{Nd}\mathrm{Ni}{\mathrm{O}}_{3}$ from room temperature down to $16\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. A clear slowing of electronic relaxation is reported when system becomes insulating. Two characteristic times found insulating phase while a single one observed metallic state. Moreover, magnitude transient reflectivity exhibits drastic increase Finally, hysteresis response...

In this work a systematic comparison of DC electrical conductivity and IR optical properties thin films , where R = Sm or Eu, is performed. Independently the nature R, it confirmed that metal–insulator transition temperature (TMI) in as well RNiO3 driven by mean lattice distortion quantified tolerance factor perovskite. The internal chemical pressure decrease due to substitution Nd another rare earth element with smaller cationic radius gives rise an increasing resistivity metallic state...

The reversible charge ordering transition of (Sm1−x,Cax)MnO3 is associated with strong changes in electrical, magnetic, and infrared properties. In this work, normal spectral emissivity calculated from reflectance bulk polished ceramics. Emissivity versus temperature shows a sharp variation at the near room temperature. By comparing apparent sample absolute temperature, we show that Sm0.35Ca0.65MnO3 good candidate for furtivity around

The synthesis of NdNiO3 perovskite structure was achieved by soft post deposition annealing initially amorphous thin films reactively sputter deposited on silicon substrates. physical measurements were fully consistent with the properties expected for thermochromic phase. Upon heating, optical transmission that correlated electrical decreased in infrared domain showing a effect this region. metal–insulator transition temperature found to be −68 °C specimen tested and jump resistance at 1.4...

This work focus on the oxidation states of nickel in NdNiO3, Nd2NiO4, and NiOx thin films deposited by reactive magnetron sputtering. Thin with a high Ni3+ content have been reached ternary oxides using soft subsequent annealing air. In order to understand presence state, present establishes comparative study between Nd–Ni–Ox at room temperature conditions different oxygen partial pressures. Crystallographic phases systematically identified X-ray diffraction showing crystallized amorphous...

Experiments performed by x-ray reflectivity, grazing incidence small angle scattering (GISAXS), and transmission electron microscopy (TEM) on a cosputtered nanocermet thin film of $\mathrm{Pt}\ensuremath{-}{\mathrm{Al}}_{2}{\mathrm{O}}_{3}$ are presented. It is shown that the morphology such heterogeneous material can be well interpreted combining information obtained from three techniques. In particular, layering metal nanoparticles in immediate vicinity substrate clearly evidenced. GISAXS...