Characteristics and optical spectra of V:YAG crystal grown in reducing atmosphere

V2O5 xerogel electrodes with much enhanced lithium-ion intercalation properties with N2 annealing

“…The film annealed in air did not have a color change and remained a yellowish color, but the film annealed in nitrogen turned from yellow to dark green, indicating the presence of V 4+ and V 3+ valence states. 28,29 The shapes of the absorption spectra of the two films were found to be similar, but the absorption band edge of the film annealed in nitrogen was $545 nm, corresponding to a bandgap of $2.28 eV; while $525 nm and $2.37 eV were found for the air annealed film, which agreed well with the reported values between 2.3 and 2.4 eV of V 2 O 5 bulk film. The reduced bandgap suggested the presence of extra energy states, probably due to the formation of low valence state vanadium ions such as V 4+ .…”

Complimentary effects of annealing temperature on optimal tuning of functionalized carbon–V2O5 hybrid nanobelts for targeted dual applications in electrochromic and supercapacitor devices

“…The film appears dark green in color, which is an indirect evidence of the presence of V 4+ ions. 36 The characteristics peaks of pristine V 2 O 5 in the low 2 θ regions 15.3° (200), 20.26° (001), and 21.7° (110) do not appear for C@V 2 O 5 @250. This suggests incomplete formation of α-V 2 O 5 .…”

Optical Crystals for 1.3 μm All-Solid-State Passively Q-Switched Laser

“…It utilizes the saturable absorption effect to modulate the loss in the laser cavity for realizing the Qswitching process. V 3+ :YAG [8] and Co 2+ :LaMgAl 11 O 19 ( Co:LMA) [9] are the most commonly used in the 1.3 µm band. Their ratios of the excited-state absorption cross section to the ground-state absorption cross section are approximately 0.1 and 0.2, respectively.…”