Nanostructured Y‐doped ZrO₂ powder: peculiarities of light emission under electron beam excitation

Abstract

Present work deals with the study of luminescence and structural properties of Y‐doped ZrO2 nanopowders sintered by co‐precipitation of Zr and Y nitrates. The structural and light emitting properties were controlled by X‐ray diffraction, transmission electron microscopy, Raman scattering, photo‐ (PL) and cathodoluminescence (CL) methods. Generally, room temperature PL spectra showed several bands in UV‐orange range, whose shapes depend on the excitation light wavelength. Along with this, CL spectra demonstrate additional “red” emission, which intensity exceeds that of other CL bands. At lower temperatures, preferable enhancement of “red” CL band, its narrowing and peak position shift to the longer wavelengths were found. This behavior testifies to the non‐elementary nature of “red” CL band. Its nature and mechanism of its excitation are discussed. It is supposed that some impurities (such as Fe and/or Zn) or complex defects, containing oxygen vacancies and these impurities, are responsible for “red” emission appeared under electron beam excitation only. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Oxygen Hole States in Zirconia Lattices: Quantitative Aspects of Their Cathodoluminescence Emission

“…The positively attractive field of this charged defect can easily trap one electron, forming the F 0 center. As reported by different authors, the relaxation process results in the luminescence emission centered around 430–460 nm. , In this case, according to the present fitting procedure, we found the major sub-band contribute around 485 nm. Considering that no dopant is present and the hafnia impurities generate a high wavelength luminescence, we should attribute this band to the intradefect transition in F + center, even though it is shifted respect to the mentioned reference.…”

CO–PROX reactions on copper Y2O3-ZrO2 catalysts prepared by a single step co-precipitation technique

“…Consequently, the main contribution to XRD patterns of 1%Cu-YZr and 8%Cu-YZr samples calcined at 600˚C is proposed to arise from a tetragonal phase. This conclusion was supported by Rietveld analysis [31,34]. Focusing now on the samples annealed at 800°C, the appearance of a small peak at 2q~28° testifies to the presence of a low amount of monoclinic phase (JCPDS 37-1484).…”

“…phases are close to each other. Therefore, to discriminate unambiguously these phases, the peaks in the range of 2q=73-75° are usually used [31][32][33] because cubic ZrO2 phase shows in this range only a single peak (at 2q~74.33°), while the tetragonal phase demonstrates two peaks (at 2q~73.05° and 74.58°). Since XRD peak positions depend on the doping [31,34], further analysis of XRD patterns will be performed for this specific range taken into account the number of XRD peaks only.…”

Structural and Luminescent Properties of (Y,Cu)-Codoped Zirconia Nanopowders

“…This means that they consist of several overlapping components that is typical for pure and Y-doped ZrO 2 materials. 8,17,25 and the references therein On the other hand, this variation implies that besides the common intense excitation at ∼280 nm, PL bands possess the individual excitation features. Unfortunately, these latter cannot be clearly separated due to significant overlapping of PL bands.…”

“…12 For successful application of ZrO 2 -based nanopowders, an achievement of the state of weakly bound single nanocrystals is one of the main problems. Among different approaches for nanopowders' production, microwave hydrothermal synthesis, 1 high-temperature solid state reaction (ceramic powders), 13 sol-gel technique, 12,14 spraypyrolysis approach 15,16 and chemical co-precipitation method 10,17,18 were used. The latter is one of the most widespread methods due to low cost and opportunity for industrial production of powders with prescribed chemical composition.…”