Defect reactions of implanted Li in ZnSe observed by $\beta$-NMR

Using $\beta$-radiation-detected nuclear magnetic resonance ($\beta$-NMR), we investigated the microscopic behavior of implanted $^{8}$Li in nominally undoped ZnSe crystals. From the temperature-dependent amplitudes of high-resolution NMR spectra we conclude a gradual interstitial-to-substitutional site change between 200 and 350 K. This is in accordance with earlier emission channeling results. We argue that this conversion proceeds via Li$_{i}^+$ + V$_{\textrm{Zn}}^{2-}$ to ${\textrm{Li}}_{\textrm{Zn}}^{-}$ and involves implantation-related Zn vacancies. (13 refs).