The effect of alloying on thermal displacements in uranium and plutonium alloys and the mechanism of stabilization of high-temperature phases by alloying

Blanter, M. S.; Глазков, В. П.; Соменков, В. А.; Orlov, V. K.; Laushkin, A. V.

doi:10.1134/s0031918x06020086

Cited by 5 publications

(6 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The highest value of the displacement is observed along the a axis where the interatomic spac ings are the least. This conclusion is verified by the previously published results concerning the diffraction studies of the anisotropy of thermal oscillations in ura nium [31,32].…”

Section: Application Of the Suggested Potential For Computation Of Prsupporting

confidence: 91%

New interatomic potential for computation of mechanical and thermodynamic properties of uranium in a wide range of pressures and temperatures

Smirnova

Starikov

Stegaĭlov

2012

Phys. Metals Metallogr.

View full text Add to dashboard Cite

A new interatomic potential for uranium is proposed. The potential is constructed in terms of the embedded atom method (EAM). As the reference data used for the optimization of potential functions, the values of forces, energies, and stresses obtained from ab initio computations have been employed. The poten tial has been applied for studies of properties of crystalline phases of uranium. It has been established that the lattice parameters of the α and γ phases, the elastic moduli, the isochore, the room temperature isotherm, and the energies of vacancy formation are in good agreement with the available experimental data and calculated results in the framework of the density functional theory. The potential suggested facilitates simulation of the first order phase transitions between γ uranium and liquid and between γ and α uranium. The melting points of uranium at pressures of up to 80 GPa, and the temperature of the phase transition between the γ phase and α phases, at ~3 GPa have been determined. For the first time, atomistic simulation of the phase transition between α and γ phases of uranium has been performed.

show abstract

Section: Application Of the Suggested Potential For Computation Of Prsupporting

confidence: 91%

New interatomic potential for computation of mechanical and thermodynamic properties of uranium in a wide range of pressures and temperatures

Smirnova

Starikov

Stegaĭlov

2012

Phys. Metals Metallogr.

View full text Add to dashboard Cite

show abstract

“…Determining the mean-square atom displacements in initial samples and their comparison to the data obtained by other groups [22,23], both experimental and computational, shows that these displacements are largely originated from thermal vibrations. Since the sample was kept at room temperature, it can be concluded that the increase of mean-square atomic displacements in self-irradiation mainly results from static displacements; but in all cases the value of static displacements proves to be lower than that of dynamic ones.…”

Section: Resultsmentioning

confidence: 98%

“…The evolution of mean-square atomic displacements in aging d-alloy Pu 242 -Ga. The levels of thermal displacements are indicated according to [22,23]. The line is a guide to the eye.…”

Section: Discussionmentioning

confidence: 99%

“…The Debye-Waller factor can be measured by X-ray and neutron diffraction. The temperature dependence of mean-square atom displacements hu 2 i has been extensively studied in the literature [22,23], yet there is no information available on the change of this quantity during selfirradiation process. Thus, the main objective of the present research is to study the change of the value of hu 2 i by neutron diffraction during long-lasting self-irradiation of Pu-Ga alloys.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Research on long-time self-irradiation of alloy δ-Pu242–Ga

Соменков¹,

Blanter²,

Глазков³

et al. 2011

Journal of Nuclear Materials

View full text Add to dashboard Cite

“…They can be measured with the help of X ray or neutron diffraction. In the literature, there can be found studies of the temperature dependence of root mean square atomic displacements 〈u 2 〉 [28,29], but no data on their changes during self irradiation are available. Therefore, this work was aimed at neutron diffraction study of changes in the 〈u 2 〉 parameter dur ing long term self irradiation of Pu-Ga alloys.…”

Section: Introductionmentioning

confidence: 99%

Neutron diffraction analysis of atomic displacements in δ-Pu-Ga alloys upon long-term self-irradiation

Blanter

Глазков

Laushkin

et al. 2012

Phys. Metals Metallogr.

Self Cite

View full text Add to dashboard Cite

The process of self irradiation of a Pu-Ga alloy has been studied by the neutron diffraction method with the determination of the crystal structure and root mean square atomic displacements 〈u 2 〉 (from the data on the Debye-Waller factor). The analysis was carried out at room temperature on the sample with an fcc structure prepared on the basis of a Pu 242 isotope feebly absorbing neutrons, in which a quickly decaying Pu 238 isotope (1.4 at %) was added to intensify self irradiation processes; this accelerated the aging processes by four times and allowed achieving the maximum equivalent self irradiation time of ~23.5 years. The fcc structure was preserved during all this time interval. An analysis of the small angle neutron scattering has demonstrated that the sample also contained precipitates with a size of a few hundreds of microns, which did not change during the aging. A change in 〈u 2 〉 (due to static displacements) occurs in two stages, i.e., a relatively rapid growth (by about 50%) during the first 5-6 years of self irradiation, and a slow decrease in the subsequent 6-23 equivalent years to nearly the magnitude that exceeds the initial value by ~20%. The latter stage can be explained by the sinking of continuously generated point defects to helium bubbles and dislocations loops accu mulating with time. The extrapolation of the decrease in 〈u 2 〉 to large aging times demonstrates that if the mech anism of point defect accumulation initiated at the first stage of the self irradiation does not change with time, the growth of 〈u 2 〉 will disappear by about 50 years of equivalent time of self irradiation.

show abstract

The effect of alloying on thermal displacements in uranium and plutonium alloys and the mechanism of stabilization of high-temperature phases by alloying

Cited by 5 publications

References 11 publications

New interatomic potential for computation of mechanical and thermodynamic properties of uranium in a wide range of pressures and temperatures

New interatomic potential for computation of mechanical and thermodynamic properties of uranium in a wide range of pressures and temperatures

Research on long-time self-irradiation of alloy δ-Pu242–Ga

Neutron diffraction analysis of atomic displacements in δ-Pu-Ga alloys upon long-term self-irradiation

Contact Info

Product

Resources

About