YAG Yttrium Aluminate Garnet

Transparent YAG ceramics (yttrium aluminate garnet, Y3AI5O12) have excellent optical and mechanical properties. Besides flieir widespread applications in solid-state lasers, transparent YAG ceramics have also been used as envelopes in lamps [10, 11]. As expected, the corrosion resistance of YAG to rare-earth halide fills was less than that of PCA. For instance, the wall could be attacked by the rare-earth halide fills (Reis), such as Tmis, after a prolonged duration of application, due to the following reaction  

As a consequence, yttrium emission lines could be detected, while color shift and voltage drop in the YAG/Rels lamps could be observed, as shown in Fig. 10.2. Therefore, it is necessary to find less corrosive fills for YAG lamps. 

---