Phase transition control, melt growth of (Gd,RE)F 3 single crystal and their luminescent properties

• Published in: Journal of luminescence Vol. 129; no. 12; pp. 1646 - 1650
• Main Authors: Yoshikawa, Akira, Jouini, Anis, Kamada, Kei, Boulon, Georges, Nikl, Martin, Saito, Fumio
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2009
• Subjects: Fluoride; Growth from melt; Luminescent materials; Phase transition; Fluoride; Luminescent materials; 74.62.Bf; 64.70.K; 78.55.−m; Growth from melt; 81.10.Fq; Phase transition
• ISSN: 0022-2313; 1872-7883
• DOI: 10.1016/j.jlumin.2009.03.040

Rare-earth sesquifluorides with no absorption in visible spectral region, such as LaF 3, GdF 3, LuF 3, YF 3, ScF 3, are the topic of intense study as a host for luminescence materials. However, except Nd:LaF 3, they are not studied as a host for laser materials. The main obstacle troubling further study of GdF 3, LuF 3, YF 3, ScF 3 single crystal is the fact that there is first-order phase transition (LaF 3 type↔beta-YF 3 type for GdF 3, alpha-YF 3 type↔beta-YF 3 type for the rest) between the room and melting temperature.To prevent the phase transition, first of all, we have tried to make solid solution between GdF 3 and YF 3 in such a way that the average cation radii can be shifted to the size that does not have phase transition. Ce 3+ perturbed luminescence was observed in the Ce- and Sr-codoped GdF 3–YF 3 system. Similar solid solution concept was applied to the combination between GdF 3 and YbF 3. The emission spectrum of Yb 3+ that exhibits broad bands around 1 μm was observed. Room temperature up-conversion luminescence spectra of Pr 3+-doped Gd 1− x Yb x F 3 were studied and visible emission from Pr 3+ was obtained under infrared laser pumping in the Yb 3+ broad absorption band at 935.5 nm.