Abstract
Schwartz, et al., previously reported calorimetry measurements conducted on a Pu-Pu6Fe mixture, from which they derived a melt enthalpy of 31.2 J/g (46.6 kJ/mol) for Pu6Fe. This was the first—and remains the only—such value to appear in the literature. We reanalyze those results in light of two contributions to the measured heat flow not considered in the original report: the melt enthalpy of the excess Pu and the subsequent heating of the liquid mixture. These corrections yield a revised value of 24.4 J/g (36.3 kJ/mol), which we show to be consistent with the melt enthalpy of U6Fe.
Highlights
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations
All of the excess Pu melted, accompanied by enough Pu6 Fe to yield a liquid of composition given by the liquidus curve at Teu ; this liquid composition is indicated by (2)
We have reanalyzed the differential scanning calorimetry (DSC) data of Reference [3], beginning with reestimation of the measured heat flow associated with the α → β transition in pure Pu. This produced slight adjustment of the sample composition, which was combined with the liquidus curve of Reference [7] to estimate the heat absorbed by the accumulating liquid once melting began. This heat was added to the melt enthalpy of pure Pu at the eutectic temperature to yield a substantially revised melt enthalpy for Pu6 Fe
Summary
Tobash, and Richmond (STR) recently reported differential scanning calorimetry (DSC) measurements on Pu6 Fe [3], providing the first estimate of its melt enthalpy Because this was—and currently remains—the only measurement of ∆Hfus available in the literature, STR compared their value to that of U6 Fe. Because this was—and currently remains—the only measurement of ∆Hfus available in the literature, STR compared their value to that of U6 Fe The aims of this brief report are to (1) demonstrate that the STR analysis is incorrect, yielding a ∆Hfus almost 30% higher than what was measured; (2) provide a corrected estimate of ∆Hfus based on reanalysis of the data; and (3) propose a consistency check superior to straightforward comparison with ∆Hfus in related materials such as U6 Fe. The first experimental Pu6 Fe phase diagram was published in 1955 [4], reproduced with considerably more detail in 1957 [5].
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
