Luminescence Properties of Rare‐Earth‐Activated Gadolinium Fluoride (GdF₃) and Oxyfluorides (GdOF)

Abstract

The luminescence properties of REa+-activated GdF, and GdOP are studied for both uv and X-ray excitation. GdOF exists in two modifications, an orthorhombic and a tetragonal one and both are used as a matrix. GdF, is activated with Pr3+, Sm3+, Tb3+, Dy3+, ErS+, and Tm3+ and with a transition metal ion, viz. Mn2+. Both modifications of GdOF are activated with Tb3+, Er3+, and Tma+. Especially the Tb3+-activated samples are very efficient green phosphors under both uv and X-ray excitation.Die Lumineszenzeigenschaften der SE3+-aktivierten Verbindungen GdF, und GdOF werden sowohl unter UV-als Rontgenstrahlanregung untersucht. GdOF existiert in zwei Phasen, eine mit orthorhombischer und eine mit tetragonaler Struktur. Beide Phasen werden als Wirtsgitter verwendet. GdF, wird mit Pr3+, Sm3+, Tb3+, Dy3+, Era+ und Tm3+ und rnit einem tfbergangsmetallion, nLmlich Mn2+-aktiviert. Beide GdOF-Phasen werden mit Tb3+, Era+ und Tm3+ aktiviert. Besonders die Tb3+-aktivierten Proben sind griine Luminophore mit hoher Ausbeute, sowohl unter W-als auch unter Rontgenstrahlanregung.

A search for luminescence of the trivalent manganese ion in solid aluminates

“…The low value of the crystal field on the Mn 2+ ion is partly due to the 12-fold coordination of the La 3+ ions in perovskite and partly due to the effectively negative charge of the Mn 2+ ion. Also GdF3:Mn 2+ shows a green emission (9). Due to a considerably stronger crystal field, the Mn 2+ emission in AI203 is located at 600 nm.…”

In Situ Local Temperature Mapping in Microscopy Nano‐Reactors with Luminescence Thermometry

“…At the highest temperatures probed thermal stability of fluorides needs to be considered. It is well known that (microcrystalline) fluorides are converted to oxyfluorides at temperatures between 600 and 800 °C in air . This limits the applicability for temperature sensing in air to the presently reported temperatures of ∼600 °C.…”

“…It is well known that (microcrystalline) fluorides are converted to oxyfluorides at temperatures between 600 and 800°C in air. [38,39] This limits the applicability for temperature sensing in air to the presently reported temperatures of~600°C. The thermal stability of nanocrystalline NaYF 4 is lower and for high temperature sensing up to 600°C a protective silica shell around the nanocrystalline NaYF 4 core is needed to allow for temperature sensing up to 600°C.…”

Energy Transfer from Gd3+ to Er3+ in Y0.34Gd0.65Er0.01F3

“…8, where the data have been normalized to match the experimental data at 290 K. The results labeled "calculated (a)" were found using [p23-(l)]calc and [p23,(2)]calc determined by (6), and the results "calculated (b)" were found using [p23,(1)]ca,c and [p23,(2)]ca,c as the measured rates weighted with the factors given in Table 1.…”

“…We study this transfer in the system Yo,34Gdo,65Ero,olF3. The Gd to Er transfer was first observed by Lammers and Blasse [6] in GdOF, but was found to be an inefficient process. In our system, the transfer is temperature dependent, and is as high as 80% efficient.…”