13775-06-9Relevant articles and documents
Friedmann, H. A.,Weaver, C. F.,Grimes, W. R.
, p. 3131 - 3133 (1970)
Toth, L. M.,Gilpatrick, L. O.
, p. 1509 - 1513 (1973)
Optical spectrum and crystal-field analysis of uranium trifluoride
Karbowiak,Drozdzyński
, p. 187 - 196 (2007)
The first low temperature absorption spectrum and crystal-field analysis of uranium trifluoride are presented. The measurements have been performed on a polycrystalline sample in the 4000-30,000 cm-1 range at 4.2 K. One may notice the largest crystal-field splitting of SLJ multiplets among all so far reported data for uranium(III) as well as in polycrystalline samples and U3+ doped single crystals. In the presented analysis 94 experimental crystal-field levels, observed in 0-24,116 cm-1 energy range, have been identified and fitted to a semiempirical Hamiltonian representing the combined atomic and crystal-field interactions at the C2 site symmetry. In order to exclude a possible influence of inaccuracy in the description of the free-ion multiplets on crystal-field parameters a number of additional freely varied parameters associated with the centroids of the free-ion multiplets were introduced. In the final step of the fitting procedure eight free-ion and 14 CF parameters were freely varied giving B02 = - 833 (45), Re B22 = 272 (36), B04 = 1817 (89), Re B24 = 186 (106), Im B24 = 776 (82), Re B44 = 523 (104), Im B44 = + 1460 (58), B06 = 1081 (105), Re B26 = - 841 (89), Im B26 = - 2459 (74), Re B46 = - 665 (88), Im B46 = - 1024 (74), Re B66 = 1416 (56), Im B66 = - 1682 (93) and r.m.s. = 24 cm-1. The performed calculation procedure enabled the determination of good starting values, reliable crystal-field parameters and a small r.m.s. deviation.
Studies on (2UF4 + H2 = 2UF3 + 2HF) and vapour pressure of UF3
Roy, K. N.,Prasad, Rajendra,Venugopal, V.,Singh, Ziley,Sood, D. D.
, p. 389 - 394 (1982)
Equilibrium constants for 2UF4(s) + H2(g) = 2UF3(s) + 2HF(g) have been measured in the temperature range 967 to 1120 K.The results can be expressed in the form: log10K = (6.35 +/- 0.17)-(12270 +/- 78)(K/T).The results have been tr
Toth, L. M.,Gilpatrick, L. O.
, p. 2799 - 2803 (1973)
Matrix IR spectra of the products from F2, ClF, and Cl2 reactions with pulsed-laser evaporated uranium atoms
Hunt, Rodney D.,Thompson, Craig,Hassanzadeh, Parviz,Andrews, Lester
, p. 388 - 391 (2008/10/08)
Pulsed Nd:YAG laser ablated uranium atoms were codeposited with F2 and excess Ar onto a CsI window at 12 K. Infrared spectra revealed the presence of several uranium fluorides including the previously characterized UF4, UF5, and UF6. Lower laser energy favored new absorptions at 400, 446, 496, and 561 cm-1. These product absorptions increased stepwise during annealings which permitted diffusion and reaction of the fluorine. Similar studies with ClF produced the above absorptions plus a new band at 554 cm-1 which is tentatively assigned to ClF2-. The first bands appearing at 400 and 446 cm-1 are assigned to UF and UF2, respectively. The 496- and 561-cm-1 bands are tentatively assigned to UF3 and F3-, respectively. Finally, uranium atoms were reacted with Cl2. In addition to several absorptions due to UCl4, a new doublet at 312 and 308 cm-1 is assigned to UCl2.
