14 resultados para LANTHANUM OXIDES

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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We demonstrate a multicore multidopant fiber which, when pumped with a single pump source around ∼800 nm , emits a more than one octave-spanning fluorescence spectrum ranging from 925 to 2300 nm . The fiber preform is manufactured from granulated oxides and the individual cores are doped with five different rare earths, i.e., Nd3+ , Yb3+ , Er3+ , Ho3+ , and Tm3+ .

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The molecular and ionic composition of saturated vapor over lanthanum triiodide was studied by Knudsen effusion mass spectrometry. The (LaI3)n molecules (n = 1–3) and the [I(LaI3)n]− ions (n = 0–4) were observed. The partial pressures of the molecules were determined and the enthalpies of sublimation, ΔsH° (298.15 K) in kJ mol−1, in the form of monomers (304 ± 7), dimers (428 ± 25), and trimers (455 ± 50) were obtained by the second and third laws of thermodynamics. The enthalpy of formation, ΔfH° (298.15 K) in kJ mol−1, of the LaI3 (−376 ± 10), La2I6 (−932 ± 25), La3I9 (−1585 ± 50) molecules and the LaI4− (−841 ± 24), La2I7− (−1486 ± 32) ions were determined. The electron work function, φe = 3.5 ± 0.3 eV, for the LaI3 crystal was calculated from the thermochemical cycle.