Thermogravimetric and differential thermal analysis of europiumIII oxalate and some europiumII salts

Glasner, A.; Levy, Ezra; Steinberg, M.; Bodenheimer, W.

doi:10.1016/0039-9140(64)80049-7

Cited by 19 publications

(12 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the gradual transition from oxalate to carbonate illustrated by the spectra of Fig. 4; and in particular, the decrease in the 780 cm -1 peak, is identical to that obtained by Glasner for the transformation of europium oxalate to carbonate [12,13]. These results coupled with the thermogravimetric data indicate that the change in slope of the weighttemperature curve around 200 ~ Fig.…”

Section: Discussionsupporting

confidence: 80%

“…This same phenomena was observed and discussed by Simons and Newkirk [16] and was attributed to the reaction CO + 1/2 02 ~ CO~ (11) which liberates 67.7 kcal/mole CO at 700 K [17]. By analogy with his studies of the thermal decomposition of europium oxalate [12,13] Glasner has postulated a carbon monoxide catalyzed mechanism to explain the reduction of Pu(C~O~)2 9 6 H~O [7].…”

Section: Discussionsupporting

confidence: 55%

“…Analogous behavior has been shown for several transition metal oxalates and investigated in some detail for europium oxalate [12,13].…”

Section: Discussionmentioning

confidence: 70%

“…Elementary carbon is often found in the decomposition products of oxalates [12,13,16] and its formation during the decomposition of calcium oxalate has been studied by Simons and Newkirk [16]. The explanation offered is that the carbon monoxide formed during the thermal decomposition, e.g.…”

Section: Discussionmentioning

confidence: 98%

“…This peak is indicative of the presence of carbonate [15]. While we are unable to present the spectrum of plutonium carbonate for comparison because the dry compound is not stable [14] the 830 cm -1 peak occurs in approximately the same position as one of the carbonate peaks in the spectra of a number of other carbonates [12,13,15]. Unfortunately, the principal carbonate band which is centered at about 1450 cm _1 [15] is obscured by two strong oxalate bands at 1300 and 1600 cm -1 as well as one of the Nujol peaks.…”

Section: Discussionmentioning

confidence: 99%

See 4 more Smart Citations

The thermal decomposition of Plutonium (IV) oxalate hexahydrate

Nissen

1980

Journal of Thermal Analysis

View full text Add to dashboard Cite

The thermal decomposition of Pu(C204).. 9 6H20 has been studied in both argon and oxygen using a combination of thermogravimetry and infrared spectroscopy. Decomposition in an inert atmosphere involves reduction of the cation to the trivalent state and its subsequent reoxidation to form PuO 2. In an oxidizing atmosphere, with unrestricted access of oxygen, reduction of the cation does not take place and decomposition to PuO 2 is through the oxycarbonate. The reduction of Pu(IV) appears to take place by a carbon monoxide catalyzed mechanism and the presence of carbort in the PuO,, decomposition product is attributed to the disproportionation of CO.Of the several processes used to prepare plutonium metal the most widely used involves the thermal decomposition of Pu(C204)2 " 6 H20 to the oxide (PuO2),. fluorination of the oxide to PuF 4 and the subsequent reduction of the fluoride to the metal with calcium. One particular disadvantage of this process is that the carbon which apparently arises as a consequence of the thermal decomposition of the oxalate, is carried through the process and appears as an impurity in the plutonium metal product. To aid in the removal of this carbon impurity the thermal decomposition of Pu(C20~)2 ' 6 H20 is done in air at 300 to 400 ~ Several earlier studies have been done on this process [1][2][3][4][5][6]. However, the interpretations were at variance with each other and as Glasner points out [7], the thermogravimetric results have had little support by other experimentation or observation.The present study makes use of both infrared spectroscopy and thermogravimetric techniques to follow the thermal decomposition of Pu(C20~)~" 6 H20 in both argon and oxygen to try to define explicitly the source of the carbon and to determine the effect, if any, of oxygen on the mechanism of the thermal decomposition of Pu(C~,O4h" 6 H20 itself. ExperimentalThe starting material, Pu(C2Oa)2 " 6 H20, was prepared by the method described by Harmon and Reas [8]. Briefly, this involved adding 1 M H~C204 and H202, for valence adjustment, to a Pu(NOa)4 solution (~ 4 M HNO~) held at 50 -55 ~

show abstract

Section: Discussionsupporting

confidence: 80%

Section: Discussionsupporting

confidence: 55%

“…Analogous behavior has been shown for several transition metal oxalates and investigated in some detail for europium oxalate [12,13].…”

Section: Discussionmentioning

confidence: 70%

Section: Discussionmentioning

confidence: 98%

Section: Discussionmentioning

confidence: 99%

See 3 more Smart Citations

The thermal decomposition of Plutonium (IV) oxalate hexahydrate

Nissen

1980

Journal of Thermal Analysis

View full text Add to dashboard Cite

show abstract

Zur Darstellung der Europiumchalkogenide EuS, EuSe und EuTe

Pink¹

1969

Zeitschrift anorg allge chemie

View full text Add to dashboard Cite

show abstract

Activation energy of thermal decomposition of fully dehydrated NdC2O4Cl·3H2O to NdOCl

Mulokozi

Zuru

1989

Journal of Thermal Analysis

View full text Add to dashboard Cite

An activation energy Ea = 195 kJ mol-1 has been determined for the thermal decomposition of NdC204C1 to NdOCI with simultaneous expulsion of CO and CO2. As compared with the value (127 kJ mo1-1) predicted by the Kahwa-Mulokozi empirical expression (i) + for Ln2(C204)3 (Ln = light lanthanide), the presence of C1-in the coordination polyhedron appreciably raises the activation energy, which is consistent with a corresponding increase in the covalent strength of the Ln-oxalate bond. The same conclusion regarding the strength of this bond is drawn from a study of the infrared spectrum.Mechanistically, the breaking of the Ln-oxalate bond is suggested to occur in the kinetic ratedetermining step.The thermal decomposition behaviour of the lanthanide oxalates and their derivatives LnC204X (X = C1 or Br) has been widely investigated [1-37]. The course of the reaction displays pronounced sensitivity to the nature of the bonding, not only with regard to the metal-oxalate interaction, but also as concerns the donor property of X. Those observations are explained in a neat theoretical framework. decomposition of oxalate can proceed via three alternativeThe thermal pathways:

show abstract

Thermogravimetric and differential thermal analysis of europiumIII oxalate and some europiumII salts

Cited by 19 publications

References 9 publications

The thermal decomposition of Plutonium (IV) oxalate hexahydrate

The thermal decomposition of Plutonium (IV) oxalate hexahydrate

Zur Darstellung der Europiumchalkogenide EuS, EuSe und EuTe

Activation energy of thermal decomposition of fully dehydrated NdC2O4Cl·3H2O to NdOCl

Contact Info

Product

Resources

About