Point defect properties in hcp and bcc Zr with trace solute Nb revealed by ab initio calculations

Xin, Xueshang; Wang, Lai; Liu, B.X.

doi:10.1016/j.jnucmat.2009.06.005

Cited by 33 publications

(14 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The solution energy for infinite dilution is Ω β mix (x → 0) = 0.312 eV for Zr impurity in β-Nb, and Ω α mix (x → 1) = 0.632 eV for Nb impurity in α-Zr, in agreement with previous ab initio calculations (0.61 eV for Domain [62] and 0.68 eV for Xin et al [51]). Our results are also consistent with the asymmetry observed in the phase diagram, as the high value of Ω α mix explains the very low solubility of niobium in hcp zirconium, whereas the lower value of Ω β mix corresponds to a higher solubility of zirconium in bcc niobium.…”

Section: Solution Energysupporting

confidence: 90%

See 1 more Smart Citation

Solubility in Zr-Nb alloys from first-principles

Cottura

Clouet

2018

Acta Materialia

View full text Add to dashboard Cite

The thermodynamic properties of the Zr-Nb alloy are investigated at temperatures below 890 K with ab initio calculations. The solution energies of the bcc Nb-rich and hcp Zr-rich solid solutions obtained within the framework of density functional theory are in good agreement with experimental data, although insufficient for a quantitative description of the miscibility gap, for which non configurational entropy has to be accounted for. Whereas electronic free energies can be neglected, we show, using the harmonic approximation and the density functional perturbation theory, that both solution free energies are strongly modified by the contribution related to atomic vibrations. Considering this vibrational free energy leads to a good description of the phase diagram.

show abstract

Section: Solution Energysupporting

confidence: 90%

“…The obtained values, listed in Table 1, are close to experimental data. The vacancy formation energies also agree with experiments [48][49][50], and with previous ab initio calculations [51,52].…”

Section: Dft Parameterssupporting

confidence: 90%

Solubility in Zr-Nb alloys from first-principles

Cottura

Clouet

2018

Acta Materialia

View full text Add to dashboard Cite

show abstract

“…The results will be easily included in the analytical expressions derived in this Letter. These expressions are straightforward to apply in other relevant materials, e.g., transition metals rare earth oxides [60], AlZr [61]), ZrNb [62], FeCr [63], or NiC [64][65][66]. A striking feature highlighted in this Letter which should occur in many systems is the nonlinearities of the effective vacancy formation free enthalpy, within temperature ranges for which it is conventionally admitted that an Arrhenius law is valid.…”

Section: Vxmentioning

confidence: 86%

Equilibrium Vacancy Concentration Driven by Undetectable Impurities

et al. 2015

View full text Add to dashboard Cite

By means of ab initio calculations combined to statistical mechanics, we provide new evidence that an experimentally undetectable tiny amount of impurities can be responsible for drastic changes in vacancy concentrations ([V]), inducing large deviations from an Arrhenius law even at low temperature. It is the case of O and N in α-Fe. The present finding is fully compatible with existing experiments, and changes the previous common vision that C has the dominant effect. This study provides a route for bridging the longstanding theoretical-experimental gap on the prediction of [V] in metals.

show abstract

“…The critical size for the first structural change of the Cu clusters from bcc to 9R is greater than the size of Nb clusters estimated by APT in this study. With respect to the process of precipitation of the bcc Nb phase in the ZreNb alloys, Xin and Liu have speculated that the precipitation of bcc Nb under irradiation occurs in two steps: a domain of the hcp Zr matrix first transforms into bcc Zr and then Nb atoms substitute Zr atoms in the bcc lattice [57]. Their hypothesis is based on the energy consideration of the binding energy between Nb atoms in bcc Zr and hcp Zr, derived from ab initio calculations: the formation of Nb clusters is energetically more favored in bcc Zr rather than in hcp Zr.…”

Section: Discussionmentioning

confidence: 99%