Raman spectra of the transplutonium orthophosphates and trimetaphosphates

Abstract

Raman spectra have been obtained from multimicrogram samples of crystalline transplutonium (americium through einsteinium) orthophosphates. Spectra were also obtained for americium, curium, and californium trimetaphosphates. Assignments of the major Raman bands and confirmation of the compounds' stoichiometry were made by comparison with spectra obtained in previous studies on the lanthanide phosphates. The variation of transplutonium orthophosphate vibrational frequencies as a function of atomic number was found to be smaller in magnitude than that established for the lanthanide orthophosphates.

Crystal chemistry of the monazite structure

“…146 ifornium and 251 Es einsteinium. [147][148][149] The precipitation of UPO 4 in formic acid media was also reported 150 but appears strongly doubtful regarding to the oxidation states generally stabilized for uranium in presence of phosphates (i.e. IV and VI).…”

Plutonium and americium monazite materials: Solid state synthesis and X-ray diffraction study

“…Pu 3+ PO 4 was prepared by precipitation and hightemperature decomposition of hexagonal Pu 3+ -PO 4 -0.5H 2 O. Keller and Walter [5] used the same route to prepare Am 3+ PO 4 and Cm 3+ PO 4 . Hobart et al [6] synthesized monazite containing Am, Cm, Cf, Bk and Es by precipitation from a solution of (NH 4 ) 2 HPO 4 followed by calcination at 1100°C. More recently, Burakov et al [7] studied (La, 238 Pu 3+ )PO 4 also synthesized by precipitation.…”

Applications of Vibrational Spectroscopy to Geology

“…99,342 Monazite is a natural orthophosphate formed by rareearth elements (from La to Gd) which can host large amounts of uranium and thorium. Raman data exist for many of these compounds 343,344 and correlations between band frequencies and composition have been made 345 ( Figure 18). …”