Yttrium orthovanadate
Yttrium orthovanadate is a transparent crystal. Undoped YVO4 is used to make efficient high-power polarizing prisms similar to Glan–Taylor prisms. With a chemical structure very similar to wakefieldite, it is also sometimes used as a synthetic gemstone since the former is prohibitively rare.
There are two principal applications for doped yttrium orthovanadate:
- Doped with neodymium it forms Nd:YVO4, an active laser medium used in diode-pumped solid-state lasers.
- Doped with europium it forms Eu:YVO4, the dominant red phosphor used in cathode-ray tubes especially in color TVs.
Basic properties
- Crystal structure:
- *Zircon tetragonal
- * Space group D4h
- * Lattice parameters a = b = 7.119 Å, c = 6.290 Å
- Density: 4.24 g/cm3
- Melting point: 1810–1940 °C
- Mohs hardness: glass-like, ~5
- Knoop hardness: 480 kg/mm2
- Thermal expansion coefficient:
- * αa = 4.43×10−6/K
- * αc = 11.37×10−6/K
- Thermal conductivity coefficient:
- *parallel to c-axis: 5.23 W·m−1·K−1
- *perpendicular to c-axis: 5.10 W·m−1·K−1
- Refractive indices, birefringence and walk-off angle at 45° :
- *at 0.63 μm:
- **ne = 2.2154
- **no = 1.9929
- **Δn = 0.2225
- **ρ = 6.04
- *at 1.30 μm:
- **ne = 2.1554
- **no = 1.9500
- **Δn = 0.2054
- **ρ= 5.72
- *at 1.55 μm:
- **ne = 2.1486
- **no = 1.9447
- **Δn = 0.2039
- **ρ = 5.69
- *Sellmeier equation :
- **ne2=4.59905 + 0.110534/ − 0.012267612 λ2
- **no2=3.77834 + 0.069736/ − 0.0108133 λ2