Synthesis, structure and optical properties of EuF3 film-forming material

Nanopartikel für die Aufwärtskonversion

“…Abhängig vom Ionenradius [343] des Seltenerdkations weisen die Trifluoride entweder eine trigonale (Tysonit vom Typ LaF 3 ; Raumgruppe: P3 c1) oder eine orthorhombische Kristallstruktur (Typ: b-YF 3 ; Raumgruppe: Pnma) auf. [344] Bei Raumtemperatur kristallisieren die Trifluoride der leichten Lanthanoide (Ln = La-Nd) ausschließlich in der trigonalen Form, [345][346][347][348] während die schweren Lanthanoide (Ln = Dy-Lu) und Yttrium orthorhombische TrifluoridKristallgitter [349][350][351][352] bilden. Für Ln = Sm-Tb sind die entsprechenden Trifluoride LnF 3 dimorph.…”

Defect structure behaviour in metal halides

“…LaF 3 to NdF 3 adopt the hexagonal tysonite structure, space group P3c1 (165) [7,8] where the cation is nine fold coordinated by fluorine. Compounds from SmF 3 to LuF 3 exhibit the orthorhombic Pnma (62) space group [9], here, the cation is eight fold coordinated by fluorine. Structural parameters are presented in Table 1.…”

Electronic structure and photoemission properties of EuF3 and EuCo2X2 (X = Si, Ge) compounds by ab initio methods

“…Several europium pnictidies and chalcogenides exhibit the mixed-valence phase transition ( [2] and references cited therein). In the EuF 3 compound, Eu exhibits the Eu 3+ (4f 6 ) state with possible surface valence transition to Eu 2+ state [3,4]. In polycrystalline EuT 2 X 2 , where T is the transition metal and X = Si or Ge, the valence of europium is unstable and depends on temperature, pressure and composition (Si ↔ Ge substitution) ( [5] and references cited therein).…”

“…In the calculations for the EuF 3 compound, the orthorhombic crystal structure of YF 3 type (space group: Pnma) was assumed with the atomic positions taken from [6]. For the EuCo 2 X 2 compounds the ThCr 2 Si 2 -type crystal structure (space group: I4/mmm) was assumed and atomic positions were taken from our X-ray diffraction data analysis.…”

“…For the EuCo 2 X 2 compounds the ThCr 2 Si 2 -type crystal structure (space group: I4/mmm) was assumed and atomic positions were taken from our X-ray diffraction data analysis. The calculations for all compounds were performed using the experimental lattice parameters [5,6]. The band structure calculations were performed with the use of the WIEN2k code of Blaha et al [7] based on very accurate full potential linearized augmented plane waves (FP-LAPW) method.…”