REFINEMENT OF THE MONOCLINIC AND TETRAGONAL STRUCTURES OF EU3-DOPED LIYO2 BY NEUTRON-DIFFRACTION AT 77 AND 383 K DIFFERENTIAL SCANNING CALORIMETRY, AND CRYSTAL-FIELD ANALYSIS()
Md. Faucher et al., REFINEMENT OF THE MONOCLINIC AND TETRAGONAL STRUCTURES OF EU3-DOPED LIYO2 BY NEUTRON-DIFFRACTION AT 77 AND 383 K DIFFERENTIAL SCANNING CALORIMETRY, AND CRYSTAL-FIELD ANALYSIS(), Journal of solid state chemistry (Print), 137(2), 1998, pp. 242-248
The atomic coordinates and the temperature factors of the beta- and al
pha-forms of LiYO2:5% Eu3+ at 77 and 383 K, were refined utilizing neu
tron diffraction data on a powder sample. DSC experiments on an anneal
ed sample show that the monoclinic --> tetragonal transition occurs at
69 degrees C during the heating cycle and the reverse at 67 degrees C
while cooling. Wide corridors lined by two parallel and adjacent Li-O
rows running along the [100] and [010] tetragonal directions allow fo
r the penetration of water, hence the formation of an hydrated crust a
t the surface of the grains. Theoretical crystal field parameters of E
u3+ in C-1 and D-2d site symmetries are calculated utilizing the newly
refined atomic coordinates. Experimental (empirical) crystal field pa
rameters are fitted utilizing a 387 x387 interaction matrix. (C) 1998
Academic Press.