Yttrium orthovanadate (YVO<sub>4</sub>) is a transparent crystal. Undoped YVO<sub>4</sub> is used to make efficient high-power polarizing prisms similar to GlanâÂÂTaylor prisms. With a chemical structure very similar to wakefieldite ([La,Ce,Nd,Y]VO<sub>4</sub>), it is also sometimes used as a synthetic gemstone since the former is prohibitively rare.
There are two principal applications for doped yttrium orthovanadate:
Basic properties
- Crystal structure:
- Zircon tetragonal (tetragonal bipyramidal)
- Space group D<sub>4h</sub>
- Lattice parameters a = b = 7.119 ÃÂ, c = 6.290 ÃÂ
- Density: 4.24 g/cm<sup>3</sup>
- Melting point: 1810âÂÂ1940 ðC
- Mohs hardness: glass-like, ~5
- Knoop hardness: 480 kg/mm<sup>2</sup>
- Thermal expansion coefficient:
- ñ<sub>a</sub> = 4.43ÃÂ10<sup>âÂÂ6</sup>/K
- ñ<sub>c</sub> = 11.37ÃÂ10<sup>âÂÂ6</sup>/K
- Thermal conductivity coefficient:
- parallel to c-axis: 5.23 W÷m<sup>âÂÂ1</sup>÷K<sup>âÂÂ1</sup>
- perpendicular to c-axis: 5.10 W÷m<sup>âÂÂ1</sup>÷K<sup>âÂÂ1</sup>
- Refractive indices, birefringence ( ÃÂn = n<sub>e</sub> - n<sub>o</sub>) and walk-off angle at 45ð (ÃÂ):
- at 0.63 üm:
- n<sub>e</sub> = 2.2154
- n<sub>o</sub> = 1.9929
- ÃÂn = 0.2225
- ÃÂ = 6.04
- at 1.30 üm:
- n<sub>e</sub> = 2.1554
- n<sub>o</sub> = 1.9500
- ÃÂn = 0.2054
- ÃÂ= 5.72
- at 1.55 üm:
- n<sub>e</sub> = 2.1486
- n<sub>o</sub> = 1.9447
- ÃÂn = 0.2039
- ÃÂ = 5.69
- Sellmeier equation (û in üm):
- n<sub>e</sub><sup>2</sup>=4.59905 + 0.110534/(û<sup>2</sup> â 0.04813) â 0.012267612 û<sup>2</sup>
- n<sub>o</sub><sup>2</sup>=3.77834 + 0.069736/(û<sup>2</sup> â 0.04724) â 0.0108133 û<sup>2</sup>
See also
References