Molecular-dynamics simulation of threshold displacement energies in lithium aluminate

Advances in methods to obtain and characterise room temperature magnetic ZnO

“…During 1 h at a H þ current of 60 lA on the exposed surface of the conglomerate of $0.1 cm 2 area fixed on a conducting substrate of '0.5 cm 2 , one implants the amount of $3 Â 10 18 H þ /cm 2 in the first '10 nm at an energy of 300 eV according to SRIM simulations, 22 used also to estimate the density of Zn and O vacancies produced by the implantation of the low energy H þ . Assuming a displacement energy of 18.5 eV for Zn in a pure ZnO lattice 23 the SRIM estimate gives $(3 6 2) Â 10 22 V Zn /cm 3 in the first 10 nm (the error is the maximum uncertainty due to geometrical factors). This V Zn concentration is $10 times larger than the Li concentration $3 Â 10 21 cm À3 assuming the nominal concentration of 7%.…”

Displacement cascade simulation of LiAlO2 using molecular dynamics

“…On the other hand, interstitials, vacancies, replacements and antisites were identified using the Wigner-Seitz cell method [23]. When these defects were defined in the same manner as in a previous study [8], in which a ''site'' was defined as a spherical space within a radius from the atomic position in the primitive cell, the number of detected defects was more than 10 times larger than the value implied by the NRT model [24] assuming the threshold-displacement energy (E d ) of 45 eV, which is the weighted average value of E d , obtained in our previous study [25], with respect to the stoichiometric ratio. This overestimation is inappropriate because the number of defects usually falls below the value from the NRT model [3,4,10] because of the lack of a consideration of defect recombination in the NRT model.…”

“…These results are considered to stem from the differences in E d . In our previous study [25], E d of Li, O and Al were respectively evaluated to be 22, 37 and 84 eV. Lower E d leads to more number of displaced atoms, which are expected to result in more replacements.…”

Gamma induced atom displacements in LYSO and LuYAP crystals as used in medical imaging applications

“…But the recommended value in that review (averaged over the low-index crystal orientations) is $20 eV. This is supported by a recent study on moleculardynamics simulation of threshold displacement energies in lithium aluminate (LiAlO 2 ) [25]. Averaging their results for Al over the low-index crystal orientations, T d $ 21 eV.…”