SrTiO₃ single crystal provides a good lattice match to most  materials with Perovskite structure. 
It is an excellent substrate for epitaxial growth of HTS and many oxide thin films.
SrTiO3 single crystal has also been used widely for special optical windows and as high quality sputtering target.

 

Typical Physical Properties
Crystal Structure	Cubic,           a=3.905  Å
Growth Method	Vernuil
Density	5.175  g/cm3
Melt Point	2080 oC
Hardness	6   ( Mohn)
Thermal expansion	10.4  (x10-6/ oC)
Dielectric Constant	~ 300
Loss Tangent at 10 GHz	~5x10-4 @ 300K ,       ~3 x10-4 @77K
Color and Appearance	Transparent (sometimes slightly brown based on annealing condition).  No twins.
Chemical Stability	Insoluble in water
Standard Products
As - grown boule  <100>	30 mm dia.  x 30- 50 mm  length 22 mm dia.  X 30 - 50 mm  length
As cut blank <100>	1" dia x 0.7 mm thickness 10 x 10 x 0.7 mm thickness.
Epi -polished substrates <100>, <110> or <111> ori. 1 or 2 sides polished, Ra< 7 Å	1" dia x 0.5 mm 20 x20 x 0.5mm 10x10x0.5 mm