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
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.
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 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