Crystal Structure

Orthorhombic,

Lattice Parameters

a = 12.96 A°, b = 10.56 A, c = 6.49A°

Density

3.6 g/cm³

Melting Point

~ 1000 °C

Ferroelectric  transition temperature

~810°C

Mohs Hardness

~5

Thermal Expansion Coefficients,/°C

a₁=1.01x10^^-5, a₂=1.37x10^^-5, a₃=-4.17x10^^-6

Hygroscopic Susceptibility

No

Dielectric Constant

E_eff = 13.0,

Color

Colorless

Ionic conductivity
(room temperature, 10kHz)

10^-8 S/cm

Transmitting range:

350~4500 nm

Ni^2=Ai+Bi[1-(Ci/λ)^2]-Diλ^2

index

A

B

C

D

Nx

2.15559

0.93307

0.20994

0.01452

Ny

2.38494

0.73603

0.23891

0.01583

Nz

2.27723

1.11030

0.23454

0.01995

Absorption coefficient:

< 0.05 % / cm @ 1064 nm < 4 % /cm @ 532 nm

Dimension tolerance:

±0.1mm

Flatness:

<l/8 @633nm

Surface quality: Scratch/Dig

10/5

Parallelism:

better than 30 arc sec.

Perpendicularity:

better than 30 arc min

Angle tolerance:

△q < 0.5°,△f < 0.5°

AR coating:

AR coatings

Clear aperture:

>90% central area

Transmitting wave front distortion:

less than l/8 @ 633nm