2 research outputs found
Persistent Type-II Multiferroicity in Nanostructured MnWO<sub>4</sub> Ceramics
Persistent
Type-II Multiferroicity in Nanostructured
MnWO<sub>4</sub> Ceramic
Tailoring the Composition of Eu<sup>3+</sup>-Doped Y<sub>3</sub>NbO<sub>7</sub> Niobate: Structural Features and Luminescent Properties Induced by Spark Plasma Sintering
The defective fluorite-related
Y<sub>3</sub>NbO<sub>7</sub> host lattice was doped with Eu<sup>3+</sup> ions to understand the influence of spark plasma sintering (SPS)
process on this host lattice. The intrinsic disorder due to the occurrence
of oxygen vacancies results in amorphous-type responses of the luminescent
cations, and the spectral distribution varies as a function of the
niobium content. Two spectral fingerprints of europium emissions were
clearly enhanced. The correlation between luminescence, X-ray diffraction,
and electron diffraction characterizations shows the existence of
local inhomogeneity. Indeed, the particular nonequilibrium sintering
conditions allowed pointing out a lack of miscibility within the Y<sub>3</sub>NbO<sub>7</sub> solid solution domain. Thus, the SPS pellet
is a composite of two extreme compositions. This phase demixing is
mainly induced by the pressure coupled with a current effect that
makes possible ionic migration in this Y<sub>3</sub>NbO<sub>7</sub> ionic conductive matrix