Refinement of the crystal structure of potassium triyttrium decafluoride, KY3F10

Optical spectra of Dy3+ in KY3F10 and LiLuF4 crystalline fibers

“…The structure of KYF is cubic, space group Fm3 m with cell parameter a ¼ 11.553 Å , [10], that of LiLuF is tetragonal, the space group being I4 1 and the cell parameters a ¼ b ¼ 5.167 Å and c ¼ 10.375 Å [11]. Room-temperature absorption spectra were measured with a spectroscopic system equipped with a 300 W halogen lamp fitted with a 0.25 m Spex monochromator as source, and a 1.26 m Spex monochromator with a RCA C31034 photomultiplier or a PbS NEP cell to analyze and detect the output radiation.…”

High temperature NMR approach of mixtures of rare earth and alkali fluorides: An insight into the local structure

“…In pure LiF, the fluorine atoms are considered as free fluorines not embedded into any complex. In solid yttrium fluorides, the structure is made of [YF x ] 3Àx polyhedra more or less connected by bridging fluorines [33][34][35][36][37]. In solid YF 3 , at room temperature, the structure is made of [YF 9 6À ] polyhedra.…”

“…The bridging fluorines are connecting three yttrium atoms F(3Y), while in LiYF 4 [29] and aNaYF 4 [38], all the fluorine atoms are shared between two [YF 8 5À ]. In the case of KY 3 F 10 , the two kinds of fluorines are reported with a ratio 1:3, one connecting two yttrium, F(2Y) and one three yttrium F(3Y) [33]. The corresponding 19 F chemical shifts values measured are different: À56, À67 and À59 ppm for F(3Y) in YF 3 and KY 3 F 10 respectively, À108, À82 and À89 ppm for F(2Y) in KY 3 F 10 , LiYF 4 and aNaYF 4 , respectively.…”

“…This evidences clearly a strong modification of the local structure around the yttrium in the melt. We have reported in Table 1 the 89 Y NMR chemical shifts measured for different solid yttrium fluoride compounds and the structural parameters reported in the literature [33][34][35][36][37][38]. This set of values will help us in the interpretation of high temperature data.…”

Quantum cutting effect inKY3F10:Tm3+

“…The diffraction lines can be indexed on the basis of a cubic cell with a space group Fm3m and a refined cell parameter of 11.537͑4͒ Å, in agreement with the crystal structure of KY 3 F 10 . 10 The absence of unindexed diffraction lines indicates that the reaction between the starting fluorides is completed for each sample. No significant variations in the cell parameter as function of the rare-earth rate are detected.…”