Lanthanum Fluoride LaF3:Eu3+
DownloadLanthanum Fluoride is not often used as an optical material. Lanthanum Fluoride is usually doped with Europium at a nominal level of 0.3% mole. In this form, the usual application is as the active element in an ion-selective electrode for the detection and measurement of Fluoride ions in solution.
Transmission Range
0.2 to 11 μm
Refractive Index
No = 1.506 at 0.55 μm
Reflection Loss
n/a
Absorption Coefficient
n/a
Reststrahlen Peak
n/a
dn/dT
n/a
dn/dμ = 0
n/a
Density
5.94 g/cc
Melting Point
1493°C (1)
Thermal Conductivity
5.1 W m-1 K-1 @ 300 K
Thermal Expansion
11x10-6 /K (para) 15.8x10-6 /K (perp) at 298K (2)
Hardness
Moh 4,5
Specific Heat Capacity
506 J Kg-1 K-1
Dielectric Constant
14 (3)
Youngs Modulus (E)
n/a
Shear Modulus (G)
n/a
Bulk Modulus (K)
n/a
Elastic Coefficients
n/a
Apparent Elastic Limit
n/a
Poisson Ratio
n/a
Solubility
Insoluble in water
Molecular Weight
195.9
Class/Structure
Trigonal (hex), P63/mcm (2) ,no cleavage
| µm | No | Ne |
|---|---|---|
| 0.254 | 1.656 | 1.649 |
| 0.405 | 1.618 | 1.612 |
| µm | No | Ne |
|---|---|---|
| 0.436 | 1.617 | 1.609 |
| 0.547 | 1.606 | 1.602 |
| µm | No | Ne |
|---|---|---|
Lanthanum Fluoride is grown as small ingots of about 10mm diameter as it is difficult to anneal. Doped with Europium, it is a pale yellow colour.
REFERENCES:
(1) Jones and Shand, J.Crys.Growth. 2 (1968) p3611
(2) Sher, Solomon, Lee, and Meuller. Phys.Rev. 144, p593 (1966)
(3) Electronic Processes in Ionic Crystals (OU Press, NY, 1940) p.41