Phase transitions in tricyclopentadienyl-chloro-uranium(IV), U(C(5)H(5))(3)Cl
This paper reports on a study of the structure and properties of the chloride compound in the uranium organometallic series U(C(5)H(5))(3)X. On examining a single crystal of this material, two phase transitions were found. The structure between 230 K and 78 K has been resolved at 120 K and was found to be monoclinic. X-ray powder experiments have been performed to study cell parameters as a function of temperature down to 30 K, and it was found that below 78 K a new monoclinic cell was formed. The C(5)H(5) dynamics were studied by neutron quasielastic experiments in the time of flight spectrometer at Saclay; strong scattering was seen at room temperature, which can be associated with the rotation of the C(5)H(5) rings. As the temperature is decreased, the motion slows down; results derived from this are related to the appearance of (0,K,0) peaks observed in the single crystal study, and values of the activation energy are derived.
Bibliographic Reference: Paper presented: Transphase-3, Djerba (TN), March 18-24, 1990
Availability: Available from (1) as Paper EN 35435 ORA
Record Number: 199111248 / Last updated on: 1994-12-02
Original language: en
Available languages: en