The fabrication of high-temperature windows and substrates, such as high-temperature superconductor (HTSC) substrates, frequently makes use of magnesium oxide (MgO), a crucial optical material. Using MgO material, Alfa Chemistry can produce optical components on demand in practically any shape or size according to customer specifications. Contact us if you require assistance.
Advantages and Uses of Magnesium Oxide Materials
At high temperatures, MgO material is physically and chemically stable. It is frequently used in the refractory sector for lenses, windows, mirrors, filters, and prisms due to its high thermal conductivity and low electrical conductivity. It also has a medium refractive index and a wide transmission range for coating applications in the DUV to IR spectral range.
MgO films help to adhere a wide range of oxides and fluorides to mineral glasses and typical IR substrates, as well as to pyroelectric films, ultra-high temperature crucibles, window materials for ultra-high temperature furnaces, and optical materials for the precision optics industry.
Fig 1. Transmittance spectra of magnesium oxide film, deposited at substrate temperatures Ts = 620 K (1), 630 K (2), 640 K (3), 650 K (4), 660 K (5), 670 K (6). (Lee G. W, et al. 2016)
Properties of Magnesium Oxide Materials
| Density | 3.58 g/cc |
| Molecular Weight | 40.32 |
| Solubility | 0.00062 g/100g Water |
| Class/Structure | Cubic FCC, NaCl, Fm3m, (100) cleavage |
| Melting Point | 2800 ℃ |
| Hardness | Knoop 692 with 600g indenter |
| Refractive Index | 1.7085 at 2 μm |
| Transmission Range | 0.3 ~ 6 μm |
| Reflection Loss | 12.8% at 2 μm |
| dn/dT | 19 x 10-6/℃ |
| Absorption Coefficient | 0.05 /cm at 5.5 μm |
| Apparent Elastic Limit | 138 MPA (20000 psi) |
| Youngs Modulus (E) | 249 GPa |
| Shear Modulus (G) | 155 GPa |
| Bulk Modulus (K) | 155 GPa |
| Thermal Expansion | 10.8 x 10-6/℃ at 273K |
| Thermal Conductivity | 42 W/m/K at 273K |
| Dielectric Constant | 9.65 at 1 MHz |
| Specific Heat Capacity | 877 J Kg-1 K-1 |
| Poisson Ratio | 0.18 |
| Elastic Coefficients | C11=294; C12=93; C44=155 |
About refractive index parameters.
"No" means ordinary light.
| µm | No | µm | No | µm | No |
|---|---|---|---|---|---|
| 0.171 | 2.319 | 0.180 | 2.138 | 0.191 | 2.039 |
| 0.200 | 1.986 | 0.230 | 1.892 | 0.276 | 1.824 |
| 0.310 | 1.795 | 0.382 | 1.767 | 0.436 | 1.755 |
| 0.500 | 1.754 | 0.644 | 1.734 | 1.000 | 1.723 |
| 2.000 | 1.709 | 3.000 | 1.692 | 4.000 | 1.668 |
| 5.000 | 1.637 | 6.020 | 1.596 | 7.040 | 1.543 |
| 8.070 | 1.475 | 9.090 | 1.389 | 10.640 | 1.209 |
| 0.171 | 2.319 | 0.180 | 2.138 | 0.191 | 2.039 |
| 0.200 | 1.986 | 0.230 | 1.892 | 0.276 | 1.824 |
| 0.310 | 1.795 | 0.382 | 1.767 | 0.436 | 1.755 |
| 0.500 | 1.754 | 0.644 | 1.734 | 1.000 | 1.723 |
| 2.000 | 1.709 | 3.000 | 1.692 | 4.000 | 1.668 |
| 5.000 | 1.637 | 6.020 | 1.596 | 7.040 | 1.543 |
Reference
- Lee G. W, et al. (2016). "Investigation of Optical Properties of Magnesium Oxide Films Obtained by Spray Pyrolysis Technique." IEEE 7th International Conference on Advanced Optoelectronics and Lasers (CAOL).