Shimizu H, Sato W, Mihara M, Fujisawa T, Fukuda M, Matsuta K
Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan.
Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan; Institute of Science and Engineering, Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan.
Appl Radiat Isot. 2018 Oct;140:224-227. doi: 10.1016/j.apradiso.2018.07.025. Epub 2018 Jul 21.
Interacting nature between impurity hydrogen atoms and vacancy-type defects in single crystal ZnO was investigated by means of positron annihilation lifetime spectroscopy. In order to clarify the observation of their thermal behavior, the sample was implanted with H using an electrostatic accelerator. After the implantation, the positron lifetime became shorter, which suggests that the hydrogen atoms were captured by zinc vacancies (V) to form vacancy-hydrogen complexes (V + nH). The complexes decompose by heat treatment: most of the hydrogen atoms gradually dissociate from V + nH in the temperature range 393-773 K. It was also suggested that large vacancy clusters were formed by the agglomeration of smaller clusters during the process of stepwise isochronal annealings at temperatures from 773 to 1073 K, and their decomposition took place at 1173-1373 K. Temperature-dependent thermal behaviors of hydrogen atoms and vacancy-type defects in ZnO are discussed.
