YAGTb

YAGTb refers to terbium-doped yttrium aluminum garnet, with the chemical formula Y3Al5O12:Tb3+. It is a doped rare-earth phosphor and scintillating material in which Tb3+ ions substitute for yttrium ions in the YAG host lattice.

The host lattice of yttrium aluminum garnet is a cubic garnet structure known for good optical transparency and thermal stability. When excited by ultraviolet or blue light, Tb3+ ions produce luminescence through 4f–4f transitions. The dominant emission is a green line centered around 545 nanometers, arising from the 5D4 → 7F5 transition in Tb3+. The emission bands are relatively sharp due to the shielded nature of the 4f electrons, and the exact spectrum can be influenced by dopant concentration and crystal field effects.

Synthesis of YAG:Tb can be achieved in several ways. Powders are commonly prepared by solid-state reaction or sol-gel methods, followed by annealing. High-quality single crystals can be grown using techniques such as the Czochralski process or the floating zone method. Typical terbium dopant levels range from sub-1% to a few percent; higher concentrations can lead to concentration quenching through non-radiative processes, reducing luminescence efficiency.

Applications of YAG:Tb center on its green-emitting phosphor properties. It is used in display technologies, fluorescence lighting, and other optoelectronic devices where green emission is desired. The material is also studied as a potential scintillator or laser host, and Tb-doped garnets in general are examined for spectrally selective light emission and laser applications. Compared with YAG doped with cerium, YAG:Tb offers a different emission color and has niche uses where a narrow green line is advantageous.