Zerodur®

Zerodur® is a highly homogeneous, glass ceramic whose thermal and mechanical properties are extremely stable over a wide temperature range. This porous-free material is a carefully chosen, temperature treated combination of a glass with a positive expansion coefficient and a quartz structure crystalline phase with a negative expansion coefficient. The resultant mixture provides a material with a near zero coefficient of thermal expansion. Zerodur® provides outstanding homogeneity, but due to absorption near the blue end of the visible spectrum, is rarely used in refractive applications.

Properties

• Refractive index nd = 1,5424 (587,6 nm)
• Abbe number: v_d = 56,1
• Stress optical coefficient K: 3,0 x 10^-6 MPa^-1
  (at 589,3 nm)

Mechanical

• Density: 2,53 g/cm³
• Young's Modulus: 90,3 GPa (mean value)
• Poisson's ratio: 0,24
• Knoop hardness : 620 ((HK 0,1/20 ; ISO 9385)

Thermal

• Coefficient of thermal expansion (CTE):
  • Class 0 materials: 0 ± 0,02 x 10^-6/K
  • Class 1 materials: 0 ± 0,05 x 10^-6/K
  • Class 2 materials: 0 ± 0,10 x 10^-6/K