Y3Al5O12 translucent nanostructured ceramics—Obtaining and optical properties

Y3Al5O12 nanostructured ceramics with a total transmittance of 63% at lambda = 1064 nm were obtained by low-temperature high-pressure sintering. From HR-TEM analysis, the materials were nearly pore-free and consisted of close-packed grains 20-40 nm in size. The transmittance spectrum in the visible and IR wavelength range, stationary X-ray excited luminescence and thermally stimulated luminescence were studied to characterise Y3Al5O12 nanostructured ceramics compared to single crystals of the same composition. The observed differences in the optical and luminescent properties were interpreted as a consequence of the high defect level of the nanoceramics arising from its non-equilibrium character, extremely large concentration of grain boundaries and surface states.