Green Luminescence of Divalent Europium in the Hydride Chloride EuHCl
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| Authors: | Nathalie Kunkel Daniel Rudolph Andries Meijerink Stefan Rommel Richard Weihrich Holger Kohlmann Thomas Schleid |
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| Affiliation: | 1. Inorganic Chemistry, University of Leipzig, Johannisallee 29, 04103 Leipzig, Germany;2. Current address: PSL Research University, Chimie Paristech‐CNRS, Institut de Recherche de Chimie Paris, 11, Rue Pierre et Marie Curie, 75005 Paris, France;3. Institute for Inorganic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany;4. Debye Institute, University of Utrecht, P. O. Box 80 000, 3508 TA Utrecht, The Netherlands;5. Institute of Inorganic Chemistry, University of Regensburg, Universit?tsstr. 31, 93040 Regensburg, Germany |
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| Abstract: | Luminescence properties of divalent europium in the mixed‐anion hydride chloride EuHCl were studied for the first time. Olive‐green single crystals of EuHCl (PbFCl‐type structure: tetragonal, P4/nmm, a = 406.58(3) pm, c = 693.12(5) pm, c/a = 1.705, Z = 2) resulted from the reaction of elemental europium (Eu), sodium hydride (NaH) and sodium chloride (NaCl), while powder samples were prepared from the binary components europium dihydride (EuH2) and dichloride (EuCl2). Low temperature X‐ray powder diffraction proved the absence of phase transitions for 12(2) K ≤ T ≤ 295(2) K. Bright green emission was observed under UV‐excitation and assigned to the 4f65d1–4f7 transition of divalent europium. Temperature‐dependent luminescence absorption and emission, as well as lifetime measurements were carried out on single crystal and powder samples. Surprisingly, only limited concentration quenching was found. Additionally, two emission bands (485 and 510 nm) are observed, whose intensity ratio depends strongly on temperature. In order to explain this behavior for a single Eu2+ site, we suggest either a dynamical Jahn–Teller effect in the excited 5d1 state or emission from both a 4f65d1 state and a trapped exciton state. |
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| Keywords: | Europium Hydrides Chlorides Crystal structure Luminescence Dynamic Jahn– Teller effect Trapped exciton emission |
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