Synthesis of RbREF4 (RE = Pr, Nd, Sm, Eu, and Tb) and RbRE2F7 (Dy, Ho, Er and Yb) under non-aqueous conditions

• Crystalline fluorides containing Rb and lanthanides obtained by simple synthesis.
• Structure and stoichiometry varied across the lanthanide series.
• Cubic symmetry up to Tb and orthorhombic structure from Dy to Yb was observed.
• Raman spectra of the investigated phases have been presented for the first time.
• Optical transitions from UV and PL spectra were analyzed.

Reaction of rare earth acetylacetonates with rubidium fluoride in methanol medium at room temperature produced crystalline phases and they were characterized using various analytical techniques. Fluorite structured products with RbREF4 stoichiometry were obtained for RE = Pr, Nd, Sm, Eu and Tb as revealed from their powder X-ray diffraction (PXRD) patterns, and wet chemical analysis. RbRE2F7 crystallizing in orthorhombic symmetry resulted for the rare earths from Dy to Yb as illustrated by their PXRD patterns, HR-TEM and selected area electron diffraction (SAED) techniques. While cubic RbPrF4 showed three phonon modes at 197, 281 and 324 cm−1, orthorhombic RbEr2F7 exhibited 10 modes at 128, 191, 236, 277, 341, 435, 520, 587, 642 and 726 cm−1, respectively in its Raman spectrum at room temperature. Optical transitions arising from the f-shell of the rare earth ions have been observed in UV–visible and photoluminescence spectra and analyzed.

A simple, wet chemical synthesis of RbREF4 (RE = Pr, Nd, Sm, Eu and Tb) and RbRE2F7 (RE = Dy, Ho, Er, and Yb) phases along with their characterization are described.Figure optionsDownload as PowerPoint slide