Modeling and X-ray Analysis of Defect Nanoclusters Formation in B 4 C under Ion Irradiation.

In the presented work, B₄C was irradiated with xenon swift heavy ions at the energy of 167 MeV. The irradiation of the substrate was done at room temperature to a fluence of 3.83 × 10¹⁴ ion/cm². The samples were then analyzed with the X-ray diffraction technique to study the structural modification, as it can probe the region of penetration of xenon atoms due to the low atomic number of the two elements involved in the material under study. The nano-cluster formation under ion irradiation was observed. Positron lifetime (PLT) calculations of the secondary point defects forming nanoclusters and introduced into the B₄C substrate by hydrogen and helium implantation were also carried out with the Multigrid instead of the K-spAce (MIKA) simulation package. The X-ray diffraction results confirmed that the sample was B₄C and it had a rhombohedral crystal structure. The X-ray diffraction indicated an increase in the lattice parameter due to the Swift heavy ion (SHI) irradiation. In B₁₂-CCC, the difference between τ with the saturation of H or He in the defect is nearly 20 ps. Under the same conditions with B₁₁C-CBC, there is approximately twice the value for the same deviation. [ABSTRACT FROM AUTHOR]