Phosphorescent luminescence of pure magnesium oxide transparent ceramics produced by spark plasma sintering

ABSTRACT Magnesium oxide (MgO) ceramics fabricated by Spark Plasma Sintering (SPS) method at different sintering temperatures were studied to evaluate optical properties including phosphorescent emission. All the samples were visually transparent. Especially, the ceramic sintered at 1900 °C demonstrated high transparency up to 60–70% in wavelengths range exceeding 300 nm. The phosphorescent emission originated from oxygen vacancies (F+ centers) at approximately 390 nm was observed in all the specimens. All the ceramics exhibited similar phosphorescent decay times consisting of three components of 3, 12 and 75 s. The phosphorescence was observed with naked eyes in a dark room after removing the excitation source.