Refinement of the Monoclinic and Tetragonal Structures of Eu3+-Doped LiYO2by Neutron Diffraction at 77 and 383 K Differential Scanning Calorimetry, and Crystal Field Analysis
✍ Scribed by M.D. Faucher; Ph. Sciau; J-M. Kiat; M-G Alves; F. Bouree
- Publisher
- Elsevier Science
- Year
- 1998
- Tongue
- English
- Weight
- 307 KB
- Volume
- 137
- Category
- Article
- ISSN
- 0022-4596
No coin nor oath required. For personal study only.
✦ Synopsis
The atomic coordinates and the temperature factors of theand -forms of LiYO 2 : 5% Eu 3؉ at 77 and 383 K, were refined utilizing neutron diffraction data on a powder sample. DSC experiments on an annealed sample show that the monoclinicP tetragonal transition occurs at 69°°C during the heating cycle and the reverse at 67°°C while cooling. Wide corridors lined by two parallel and adjacent Li-O rows running along the [100] and [010] tetragonal directions allow for the penetration of water, hence the formation of an hydrated crust at the surface of the grains. Theoretical crystal field parameters of Eu 3؉ in C 1 and D 2d site symmetries are calculated utilizing the newly refined atomic coordinates. Experimental (empirical) crystal field parameters are fitted utilizing a 387؋387 interaction matrix.