13760-81-1Relevant articles and documents
Experimental study of the enthalpy of lutetium trifluoride in solid and liquid states
Lyapunov,Baginskii,Stankus
, p. 7 - 9 (2004)
The high temperature enthalpy of high purity LuF3 from 395 to 1597K was measured by a drop calorimeter method. The temperature dependences of enthalpy and heat capacity were calculated. The values of heat capacity and enthalpy changes on phase transition and phase transformation were obtained. The original experimental values are presented.
Infrared spectra and quantum chemical calculations of the bridge-bonded HC(F)LnF2 (Ln = La-Lu) complexes
Gong, Yu,Wang, Xuefeng,Andrews, Lester,Chen, Mingyang,Dixon, David A.
, p. 4443 - 4452 (2011/10/10)
Lanthanide metal atoms, produced by laser ablation, were condensed with CHF3 (CDF3) in excess argon or neon at 4 K, and new infrared absorptions are assigned to the oxidative addition product fluoromethylene lanthanide difluoride complex on the basis of deuterium substitution and density functional theory frequency calculations. Two dominant bands in the 500 cm-1 region are identified as metal-fluorine stretching modes. A band in the mid-600 cm-1 region is diagnostic for the unusual fluorine bridge bond C-(F)-Ln. Our calculations show that most of the bridged HC(F)LnF2 structures are 3-6 kcal/mol lower in energy than the open CHF-LnF2 structures, which is in contrast to the open structures observed for the corresponding CH2-LnF2 methylene lanthanide difluorides. Argon-to-neon matrix shifts are 15-16 cm -1 to the blue for stretching of the almost purely ionic Ln-F bonds, as expected, but 10 cm-1 to the red for the bridge C-(F)-Ln stretching mode, which arises because Ar binds more strongly to the electropositive Ln center, decreasing the bridge bonding, and thus allowing a higher C-F stretching frequency.
Optically active uniform potassium and lithium rare earth fluoride nanocrystals derived from metal trifluroacetate precursors
Du, Ya-Ping,Zhang, Ya-Wen,Sun, Ling-Dong,Yan, Chun-Hua
, p. 8574 - 8581 (2011/01/06)
This paper reports the first systematical synthesis of near-monodisperse potassium and lithium rare earth (RE) fluoride (K(Li)REF4) nanocrystals with diverse shapes (cubic KLaF4 and KCeF4 wormlike nanowires, nanocubes and
Thermochemical studies on the lanthanoid complexes of trifluoroacetic acid
Yoshimura,Ohara
, p. 573 - 576 (2008/10/09)
The thermal decomposition of the lanthanoid complexes of trifluoroacetic acid (Ln(CF3COO)3·3H2O; Ln = La-Lu) was studied by TG and DTA methods. The Ln(CF3COO) 3·3H2O complexes decompose in several stages; first dehydrate to the anhydrous state, then followed by decomposition of the anhydrous salt to a stable product of LnF3. From the endothermic and exothermic data of Ln(CF3COO)3·3H2O complexes, pyrolysis behavior of the complexes is classified into three groups: (1) La-Pr salts; (2) Nd-Gd salts; (3) Tb-Lu salts. It has been shown that all the final decomposition products were found to result in the formation of LnF3.
Laser development of rare-earth doped crystals
Vieira Jr.,Ranieri,Tarelho,Wetter,Baldochi,Gomes,De Matos,De Rossi,Nogueira,Courrol,Barbosa,Maldonado,Morato
, p. 231 - 239 (2008/10/08)
Rare earth doped laser crystals present good optical properties providing most of the solid state lasers available today. In particular, some fluoride crystals are capable of forming solid solution with several rare earth fluorides, allowing one to take full advantage of the energy transfer mechanisms that might occur among them. LiREF4 (RE = rare earth) crystals, for example, are so flexible that in some cases the doping concentration can go up to 100%. The Nd:LiLuF4 (Nd:LuLF) system has a 1047-nm emission bandwidth 25% larger than Nd:YLF, which makes it very promising for laser mode-locked operation. Nevertheless, lutetium compounds are very difficult to obtain, therefore Nd-doped mixed crystals grown from LiF-Y1-xLuxF3 (0A new laser medium was obtained for the Nd:LiLu0.5Y0.5F4 crystal, which presents a Nd emission bandwidth close to the Nd:LuLF (1.82 nm). The mode-locked operation in a diode pumped laser system using the KLM technique was performed and pulses of 4.5 ps were readily obtained. It is also shown that the LiGdF4 (GLF) is a promising host for diode pumped high power Nd lasers which require crystals with higher dopant concentrations. Another example is the Ho:LiYF4 (Ho:YLF) laser operating at 2065 nm obtained as a result of concentration optimization of the sensitizers Er and Tm. The optimization was based on a model comprising the various energy transfer mechanisms that take place in these long lived metastable states, heavily dependent on the dopants concentration. As a quasi-four-level system, the Ho concentration must be kept very small (≤0.005 mol%). The laser operation was optimized by the dynamical coupling of pump and laser modes, and by the dopants optical cycle. These optimizations resulted in a CW Ho laser with 2 W output, in a diode pumped system operation.
Crystal chemical study of the high-temperature phase R(O,F)1.93±δ with R = Tm, Yb and Lu. Professor Dr. Georg Brauer on the occasion of his 90th birthday
Mueller,Petzel,Hormann,Greis
, p. 165 - 168 (2008/10/08)
The crystal chemistry of the non-stoichiometric compounds R(O,F)x with R = Tm, Yb, and Lu with x≈1.93±0.02, which are formed by peritectoid reaction of R2O3 with RF3 at ca. 900 K, ca. 950 K and 1076 K, respectively, has been studied by X-ray powder diffraction (Guinier method). Samples of the common composition R(O,F)1.93, which were obtained by quenching from 1375±15 K to room temperature, displayed diffraction patterns of a rather complex superstructure based on the fluorite-related parent structure. The corresponding body-centered basis structure with Z = 2 was found to be orthorhombic with the following lattice parameters: R a(angstroms) b(angstroms) c(angstroms), Tm 3.7508(2) 5.3772(3) 3.8210(2), Yb 3.7341 (2) 5.3609(4) 3.8129(3), Lu 3.7008(2) 5.3371 (4)3.8170(2). This type of compound could not be found in the system Er-O-F. It is therefore concluded that its existence is restricted to the systems with R = Tm, Yb, Lu and Sc, which are characterized by the occurrence of the monoclinic, baddeleyite-type modification of stoichiometric ROF. It could be shown that for the Tm-O-F system the parent structure formula volumes of the orthorhombic vernier phase Tm(O,F)2.11, cubic α-TmOF and orthorhombic Tm(O,F)1.93 depend approximately linearly on composition. The question, whether monoclinic baddeleyite-related TmOF, which has been described in the literature, exists as a thermodynamically stable compound, is tentatively discussed.
Thermodynamics of the lanthanide trifluorides. IV. The heat capacities of gadolinium trifluoride GdF3, lutetium trifluoride LuF3, and yttrium trifluoride YF3 from 5 to 350 deg K
Flotow, Howard E.,O'Hare, P. A. G.
, p. 3046 - 3055 (2007/10/02)
The heat capacities of three isostructural trifluorides GdF3, LuF3, and YF3 were determined from 5 to 350 deg K by adiabatic calorimetry.Below 15 deg K GdF3 contained an excess heat capacity contribution over the usual lattice heat capacity; LuF3 and YF3
PREPARATION, THERMAL CHARACTERIZATION AND X-RAY POWDER DIFFRACTION OF Ba2REF7 SUPERSTRUCTURE PHASES (RE EQUVLNT Dy-Lu, Y).
Kieser,Greis
, p. 63 - 69 (2008/10/09)
Thermal analyses on samples of the composition (Ba, RE)F//2//,//3//3 revealed seven new compounds Ba//2REF//7 (RE EQUVLNT Dy-Lu, Y). They are stable only above about 940 degree C but can be quenched after annealing for several days at 950-1000 degree C. These phases, which are metastable at room temperature, were characterized by X-ray powder diffraction. A tetragonal distortion of the fluorite parent structure was detected, analogous to that in the Ln//3F//7, Ca//2REF//7, and Sr//2REF//7 phases. In contrast, however, the superstructure is not fully pronounced and only tripling along the c axis is observed.
