The study of oxygen ion motion in Zn2GeO4 by Raman spectroscopy

• The oxygen ions undergo positional disordering along the oxygen vacancies above 300 K.
• The temperature dependence of the bandwidth of oxygen related mode is analyzed using a Arrhenius model.
• The activation energy calculated from the oxygen related mode is 0.46 eV.
• The motion of oxygen ion is described in terms of the conventional fast-ion conductor.

The temperature dependence of oxygen ion behavior in Zn2GeO4 has been studied from 78 to 873 K. As the temperature increases, the oxygen ions undergo positional disordering along the oxygen vacancies, with the oxygen related modes (ORMs) at 751 cm− 1 and 775 cm− 1 broadening and weakening dramatically. The temperature dependence of the bandwidth of oxygen ion mode is particularly interesting and a model suggested by Andrade and Porto is used to describe the linewidth of a phonon. The activation energy calculated from the ORM is 0.46 eV. Moreover, the motion of oxygen ion in Zn2GeO4 is described in terms of the conventional fast-ion conductor.