Sapphire (Al2O3) single crystal

Physical Properties of Sapphire (Al2O3)

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

CrystalPurity

> 99.99%

Melt Point

2040 oC        

Density

3.98  g/cm3  

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    ~ 11.58@ 300K at C axis

Loss Tangent at 10 GHz

< 2x10-5  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