The lattice mismatch rate between lithium aluminate single crystal and gallium nitride is very small (1.4% for lithium aluminate), making it a high-quality substrate for gallium nitride thin films.
Yttrium doped zirconia needs to be added as stabilizer, with a common concentration of 13 mol%, YSZ has the characteristics of good mechanical and chemical stability and low cost
Potassium tantalate (KTaO3, KT for short) single crystal has a stable cubic structure and can be used to make laser modulators, digital deflectors and semiconductor devices.
Yttrium aluminate (YAlO3, YAP) single crystal is an important crystal matrix material similar to YAG single crystal with excellent optical and physical and chemical properties.
Sapphire substrate is the popular substrates for III-V nitrides, superconductor and magnetic epi film due to less mis-matched lattice and stable chemical and physical properties
Rutile (TiO2) large birefringence, large refractive index, is a method for spectral prism devices such as optical isolators and the polarization beam splitter and a very good material