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Ion-induced damage accumulation and electron-beam-enhanced recrystallization in Sr Ti O 3

2005; American Physical Society; Volume: 72; Issue: 9 Linguagem: Inglês

10.1103/physrevb.72.094112

1550-235X

Yanwen Zhang, J. Lian, C. M. Wang, Weilin Jiang, Rodney C. Ewing, William J. Weber,

Ferroelectric and Piezoelectric Materials

Damage accumulation in strontium titanate $(\mathrm{Sr}\mathrm{Ti}{\mathrm{O}}_{3})$ from $1.0\phantom{\rule{0.3em}{0ex}}\mathrm{MeV}$ Au irradiation has been investigated at temperatures from $150\phantom{\rule{0.3em}{0ex}}\text{to}\phantom{\rule{0.3em}{0ex}}400\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. The relative disorder on the Sr and Ti sublattices at the damage peak has been determined as a function of local dose and temperature. A disorder accumulation model has been fit to data from this study and from the literature, indicating that defect-stimulated amorphization is the primary amorphization mechanism up to $\ensuremath{\sim}360\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. High-dose irradiation at $400\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ leads to formation of an amorphous surface layer. Analyses of the temperature dependence for amorphization indicate that the amorphization kinetics are consistent with irradiation-enhanced and thermal recovery processes with activation energies of $0.1\ifmmode\pm\else\textpm\fi{}0.05\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ and $0.7\ifmmode\pm\else\textpm\fi{}0.1\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$, respectively. Under $200\phantom{\rule{0.3em}{0ex}}\mathrm{keV}$ electron-beam irradiation, the epitaxial recrystallization rates are orders of magnitude higher than thermal rates, and an activation energy of $0.1\ifmmode\pm\else\textpm\fi{}0.05\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ is determined for the e-beam enhanced recrystallization processes.