Fig 1.
Schematic of the sample surface treatments and spectral data acquisition.
Fig 2.
PL emission spectra emitted by the 5 × 5 × 2 mm3 Ce:GAGG single-crystal samples under the 325 nm He–Cd laser excitation: (a, black) as-cut, (b, blue) mechanically polished, (c)–(h) chemically polished for ((c, neon green), (d, orange), (e, magenta), (f, red), (g, green), (h, violet)), for 10, 20, 30, 60, 90, and 120 min.
Table 1.
EDS analysis results of the Ce:GAGG crystal samples after different surface treatments.
Each value denotes an average value obtained from measurements over five different spots on the samples.
Fig 3.
XRD spectra of the Ce:GAGG samples after different surface treatments, showing peaks at: (a) ~ 32.5° and (b) ~ 60.4°.
Fig 4.
SEM images of the 5 × 5 × 2 mm3 Ce:GAGG single crystals: (a) as-cut, (b) mechanically polished, and (c)–(f) chemically polished for 10, 30, 60, and 120 min.
Fig 5.
Surface roughness measurements of the 5 × 5 mm2 Ce:GAGG face: (a) as-cut (black), (b) mechanically polished (blue), (c) chemically polished for 10 min (green), and (d) chemically polished for 60 min (red).
Table 2.
Comparison of the surface roughness and waviness values obtained after the different surface treatments.
Table 3.
Relative light output and energy resolution of the 5 × 5 × 2 mm3 Ce:GAGG single crystals before and after the different surface treatments.
Fig 6.
Example of pulse height spectra of a 5 × 5 × 2 mm3 Ce:GAGG single-crystal sample, coupled to a PMT, before and after chemical polishing: (a) as-cut and (b) chemically polished for 60 min. A 137Cs radioactive source was used to obtain the pulse height spectra.
Fig 7.
Relative light output compared to itself (as-cut) after chemical polishing for 30, 60, 90, and 120 min for various Ce:GAGG crystal thicknesses.