Author(s)

Trinh Hoa Lang, Chau Van Tao, Kieu Tien Dung, Le Hoang Chien

Faculty of Physics and Engineering Physics, University of Science, Ho Chi Minh City, Vietnam.
Swinburne University of Technology, Melbourne, Australia.

Positron annihilation in TiO₂ rutile crystal is studied by an assumption that a positron binds with valance electrons of a titanium dioxide to form a pseudo TiO_2-positron molecule before it annihilates with these electrons. The orbital modification consisting of explicit electron-positron and electron-electron correlation in each electronic orbital is used for the electrons and positron wave functions. By these wave functions, the calculation results of the positron lifetimes in unmitigated and defective TiO₂ crystals are about 170 ps, 266 ps and 243 ps, respectively. These results are in good agreement with experimental data of the positron lifetimes in vacancies of TiO₂ from 180 ps to 300 ps.

Positron; Annihilation; Jastrow; Lifetime; VQMC; TiO₂

T. Lang, C. Tao, K. Dung and L. Chien, "Positron Annihilation in Perfect and Defective TiO₂ Rutile Crystal with Single Particle Wave Function: Slater Type Orbital and Modified Jastrow Functions," World Journal of Nuclear Science and Technology, Vol. 4 No. 1, 2014, pp. 33-39. doi: 10.4236/wjnst.2014.41006.