English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Pure HfW2O8- and Ln3+-containing solid solutions, Hf1−xLnxW2O8−x/2 (Ln = Eu, Tm, Lu), were synthesized using the hydrothermal method. The lanthanide ions were selected based on the differences between their ionic radii. A content of the Ln3+ ions in the range of 0.01–0.15 mol with a step of 0.02 was used for Hf1−xLnxW2O8−x/2 preparation, although the main research was performed on x = 0.01 and 0.05 samples because of an inhomogeneity detected by powder X-ray diffraction (XRD) when the content of Ln3+ was above 0.07–0.09 mol. X-ray diffraction measurements were supported by Raman and infrared spectroscopy. A new band in the Raman spectra of the samples with 0.05 mol Ln3+, as well as a red shift of the most intensive band (assigned to valence stretching of W-O-W bonds) as a result of the Ln3+ presence, was detected. The Scanning Electron Microscopy and Transmission Electron Microscopy micrographs revealed well-crystalized microcrystals with lengths in the range of 2–5 μm, with larger interplanar distances, measured in the solid solutions of the same crystal plain. The alpha-HfW2O8 → beta-HfW2O8 order-to-disorder phase transition was followed by high temperature XRD, and its reversibility was evident. The influence of the Ln3+ both on the unit cell parameters of the solid solutions and on the temperature of phase transition and on the coefficient of thermal expansion, CTE, was observed. A band gap energy in the range of 2.8–3.1 eV for pure HfW2O8 and for the solid solutions Hf1−xLnxW2O8−x/2 (x = 0.01 and 0.05) was determined.

Characterization of Tungstates of the Type Hf1−xLnxW2O8−x/2 (Ln = Eu, Tm, Lu) Synthesized Using the Hydrothermal Method