Al2O3

Al2O3

Al2O3

Physical Properties of Sapphire
Crystal Structure Hexagonal.   a =4.758 Å   c= 12.992 Å
Crystallographic D spacing (1120 ) – a plane:  2.379 Å   (1102) – r plane:  1.740 Å
(1010) – m plane:  1.375 Å    (1123) – n plane: 1.147 ů
(0001) – c plane:   2.165 Å   (1011) – s plane:  1.961 Å
Crystal Purity > 99.99%
Melt Point 2040 oC
Density 3.98  g/cm
Hardness 9 ( mohs)
Thermal Expansion  7.5  (x10-6/ oC)
Specific Heat 0.10  ( cal / oC)
Thermal Conductivity, 46.06 @ 0 oC     25.12 @ 100 oC,
12.56 @ 400 oC        ( W/(m.K) )
Dielectric Constant ~9.4 @300K  at A axis    [email protected] 300K at C axis
Loss Tangent at 10 GHz < 2×10-5  at A axis ,       <5 x10-5  at C axis
Standard Products
As – grown boules
<0001> ori.± 0.5o
3″ dia x 50 ~ 70 mm length
2″ dia x 50 ~ 70 mm length
30 mm dia  x 150 mm  length
As-cut blanks
<0001> ori.± 0.5o
2″ dia x 0.7 mm thickness
1″ dia x 0.7 mm thickness
Epi -polished substrates
C, R, A plane: ori.± 0.5o
1 or 2 sides polished
Ra< 10 Å
3″ dia. x 0.5 mm
2″ dia. x 0.33 mm,   2″dia x 0.5 mm
1″ dia  x 0.5 mm
0.5″ x 0.5″ x 0.5 mm
10x10x0.5 mm