Density [g/cm3] | 2.51 |
Young's modulus /Gpa | 82 |
Shear modulus /Gpa | / |
Thermal conductivity W/mk | 1.1 |
Thermal expansion coefficient k(-1) | 11.8 |
Transition temperature ℃ | 657 |
Its refractive index is close to 1.5168, which is one of the largest refractive indices among common optical materials. This makes it widely used in optical design, especially in the manufacture of optical lenses, prisms, windows and other optical elements.H-K9L (N-BK7) is a glass material with excellent optical properties, mainly composed of silicon, oxygen, sodium and magnesium.