Luminescence analysis and subsequent revision of the crystal structure of triclinic L-EuBO3
Abstract
The structure of L-EuBO3 is revised by using the centric P-1 space group with two crystallographic sites for Eu3+, in perfect agreement with the luminescence results (site A and site B). The structure, refined from single crystal X-ray diffraction data, is triclinic, space group P-1, Z=4, with a=6.468(7) Å, b=6.477(7) Å, c=6.220(7) Å, α=107.78(6)°, β=108.00(7)°, γ=93.07(4)°, R1=0.025, wR2=0.062. The three-dimensional network is built up from corrugated sheets of EuO8 polyhedra, approximately parallel to the (1̄1̄1) planes. Luminescence analysis indicates that site to site energy transfer is efficient at 77 K and is phonon assisted from site B to site A. At 12 K, this site B to site A phonon coupling disappears.