two sides EPI polished with surface roughness < 5 A
Package
One 1000 class clean room with 100 class plastic bag
Features
•Good lattice match with perovskite structure superconductors •Stable structure with much less defects than SrTiO3 •Low dielectric constant suitable for microwave or high frequency application
Typical Properties
Purity
99.99%
Color
Light Brown
Crystal Structure
Tetragonal
Lattice Constabt
•a = b = 3.756 A •C = 12.636 A
Density
5.92 g / cc
Melting Point
1650 oC
Thermal Expansion Coeff.
12 ppm / oC
Dielectric Constant
•16.81 at a axis •20.02 at c axis
Loss Tangent (1 MHz, 300 K)
•6 x 104 at a axis •8 x 104 at c axis
Maximum as grown. crystal size
30 mm dia x 35 mm length
Standard Orientation
(100), (001)
Edge alignment
Available on request
Comparison of SrTiO3 - LaAlO3 - SrAlO4 Crystal
Properties/Crystal
SrTiO3
LaAlO3
SrLaAlO4
Structure
Cubic
Rhombohedral at 25 oC : Cubic at > 435 oC :
Tetragonal
Lattice Constant
a = 3.905
a = 3.821 A
a = b = 3.756 A c = 12.636
mismatch to YBCO (a = 3.9)
+0.12 %
-2.0 %
-3.7 %
Dielectric Constant
~ 300
~ 25
~ 17
Grown Method
Vernuil
CZ
CZ
Thermal expansion
10.4 (x10-6 / oC)
10 (x10-6 / oC)
12 (x10-6 / oC)
Melting point
2100 oC
2080 oC
1650 oC
Density
5.175 g/cm3
6.52 g/cm3
5.92 g/cc
Max. Crystal size
30 mm dia.
75 mm dia
35 mm dia
Crystal quality
Wide rocking curve due to dislocation density
Visible twin due to phase transition around 400 oC
