Structure cristalline de la phase β-KEr2F7. Composés isotypes

Optical properties of Eu3+:CsGd2F7 downconversion phosphor

“…The CsGd 2 F 7 is considered [14] to be isostructural with KEr 2 F 7 (orthorhombic, space group Pna2 1 [16]). The obtained powder pattern was indexed with lattice parameters: a ¼ 12:493; b ¼ 13:812 and c ¼ 8:046 ( A; in good agreement with the literature [17].…”

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

“…While the lanthanide ion is surrounded by eight fluorine atoms in fluorite structure, seven and nine coordinated lanthanide ions are present in KEr 2 F 7 structure [11]. This critical structural difference can be elucidated with the help of transitions in both the UV-visible and photoluminescent spectral techniques.…”

“…A quick search-match with the available entries in the PDF library suggested the close resemblance of the observed PXRD pattern with KEr 2 F 7 (JCPDS File no. 73-0942) crystallizing in orthorhombic system [11]. Le-bail refinement of these patterns was therefore carried out in orthorhombic symmetry (Space group Pnma #62) using TOPAS 3 software.…”

“…Rb-rare-earth (RE)-F is a less investigated system as compared to their sodium or potassium analogues and thus gives enough scope for their exploration [8][9][10][11][12][13]. Also, the role of lanthanide contraction on the choice of structure and symmetry can be understood from such a study.…”

“…Also, the role of lanthanide contraction on the choice of structure and symmetry can be understood from such a study. RbLaF 4 (prepared by the solid state reaction between RbF and LaF 3 at high temperatures) crystallizing in orthorhombic structure, fluorite structured RbGdF 4 (obtained as nanocrystals by the wet chemical synthesis) and RbEr 2 F 7 (prepared by the solid state reactions) are worth noting as they have been demonstrated to exhibit interesting optical and magnetic properties [8][9][10][11]. In this paper, synthesis of Rb-RE (RE = Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb)-F compositions by a wet chemical synthesis at room temperature and their characterizations are described.…”