User:Elisabeth at SCHOTT/Zerodur

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4-meter Zerodur mirror blank mould being opened at first annealing for the ELT secondary mirror.[1]

Zerodur[2] is a lithium-aluminosilicate glass-ceramic[3] manufactured by Schott AG.[4] Zerodur has a near zero coefficient of thermal expansion (CTE), which is used for high-precision applications in telescope optics, microlithography machines and inertial navigation systems.

History[edit]

Schott began developing glass-ceramics in the 1960s.[5] In 1966, Hans Elsässer, the founding director of the Max Planck Institute for Astronomy, asked the company if it could cast an almost 4m telescope mirror substrate from a new low-expansion glass-ceramic it had been developing.[6] In May 1969, the Max Planck Institute for Astronomy ordered 11 mirror substrates, including a 3.6m mirror blank.[7]

Since the late 1960s, Zerodur has also been applied in integrated circuit and flat panel display lithography used to produce computer chips and displays, precision measurement equipment, and ring laser gyroscopes in navigation systems.[8] Additionally, it has been used in Earth observation satellites[9] and space telescopes.[10]

Applications[edit]

The Keck II Telescope showing the segmented primary mirror made of Zerodur

The main applications for Zerodur include telescope optics in astronomy[11] and space applications[12], lithography machines for microchips and displays[13], and inertial measurements systems for navigation.[14][15]

In astronomy, it is used for mirror substrates in large telescopes such as the Keck I and Keck II telescopes[16], the Gran Telescopio Canarias[17], the Very Large Telescope[18], and Extremely Large Telescope.[19]

In space, it has been used for the primary mirror of SOFIA’s telescope[20] and for the optical bench in the LISA Pathfinder mission.[21]

In microlithography, Zerodur is used in wafer steppers and scanner machines for precise and reproducible wafer positioning.[22][23] It is also used as a mirror substrate material in refractive optics for EUV lithography.[24]

In inertial measurement units, Zerodur is used in ring laser gyroscopes.[25]

Properties[edit]

Zerodur has both an amorphous (vitreous) component and a crystalline component. Its most important properties[26] are:

  • Near zero coefficient of thermal expansion, with a mean value of 0 ± 0.007×10−6 K−1 within the temperature range of 0 to 50 °C.
  • High 3D homogeneity[27] with few inclusions, bubbles and internal stria.
  • Hardness similar to that of borosilicate glass.
  • High affinity for coatings.
  • Low helium permeability.
  • Non-porous.
  • Good chemical stability.
  • Fracture toughness approximately 0.9 MPa·m1/2.[3][28]

Physical properties[edit]

See also[edit]

References[edit]

  1. ^ "Secondary Mirror of ELT Successfully Cast - Largest convex mirror blank ever created". www.eso.org. Retrieved 22 May 2017.
  2. ^ "Zerodur®". Archived from the original on July 24, 2011. Retrieved September 4, 2011.
  3. ^ a b Viens, Michael J (April 1990). "Fracture Toughness and Crack Growth of Zerodur" (PDF). NASA Technical Memorandum 4185. NASA. Retrieved 28 August 2011.
  4. ^ "Schott AG Zerodur description". Archived from the original on February 1, 2014.
  5. ^ Haug, Reiner (1995). Zerodur® — A Low Thermal Expansion Glass Ceramic for Optical Precision Applications. Springer. pp. 107–214. Retrieved 6 May 2024.
  6. ^ Haug, Reiner (1995). Zerodur® — A Low Thermal Expansion Glass Ceramic for Optical Precision Applications. Springer. pp. 107–214. Retrieved 6 May 2024.
  7. ^ Lemke, Dietrich (2019). Im Himmel über Heidelberg (PDF). Berlin, Heidelberg: Max-Planck-Institut Für Astronomie. p. 77. ISBN 978-3-927579-25-5. Retrieved 6 May 2024.
  8. ^ Savage, Lynn (October 2011). "The Birth – and Growth – of Glass Ceramics". Photonics Spectra. Retrieved 6 May 2024.
  9. ^ Kihm, Hagyong (2022). "Development of the primary mirror for CAS500-1 (Compact Advanced Satellite 500-1)". Journal of the Korean Physical Society. 81: 473–480. doi:10.1007/s40042-022-00406-0. Retrieved 6 May 2024.
  10. ^ Krieg, Janina (2022). "The past decade of ZERODUR glass-ceramics in space applications". Proceedings of the SPIE. 12180. doi:10.1117/12.2628956. Retrieved 6 May 2024.
  11. ^ Döhring, Thorsten (May 2019). "Four decades of ZERODUR mirror substrates for astronomy". Proceedings, 4th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Large Mirrors and Telescopes. 7281. doi:10.1117/12.831423. Retrieved 10 May 2024.
  12. ^ Carré, Antoine (May 2023). "Comprehensive review of the effects of ionizing radiations on the ZERODUR® glass ceramic". Journal of Astronomical Telescopes, Instruments, and Systems. 9 (2). doi:10.1117/1.JATIS.9.2.024005. Retrieved 10 May 2024.
  13. ^ "SCHOTT Strengthens Glass Substrate Portfolio". Printed Electronics Now. September 29, 2023.
  14. ^ Sokach, Stephen. "ZERODUR: The Highly Technical Glass-Ceramic". Tech Briefs. Retrieved 10 May 2024.
  15. ^ "Zerodur". Mindrum Precision. Retrieved 10 May 2024.
  16. ^ "A Mirror's Perfect Reflection". W.M. Keck Observatory. Retrieved 10 May 2024.
  17. ^ "Description of the GTC". Gran Telescopio CANARIAS. Retrieved 10 May 2024.
  18. ^ "Very Large Telescope". ESO. Retrieved 10 May 2024.
  19. ^ "Mirrors and Optical Design". ESO. Retrieved 10 May 2024.
  20. ^ Krabbe, Alfred (June 2000). "SOFIA telescope". Proceedings, Airborne Telescope Systems. 4014. doi:10.1117/12.389103. Retrieved 10 May 2024.
  21. ^ "LISA Technology Package Optical Bench Interferometer During Calibration". ESA. Retrieved 10 May 2024.
  22. ^ Hartmann, Peter. "SCHOTT – Ultra low expansion glass ceramic ZERODUR" (PDF). Max-Planck-Institut für Astronomie. p. 49. Retrieved 10 May 2024.
  23. ^ Jedamzik, Ralf (2014). "Glass ceramic ZERODUR enabling nanometer precision". Proceedings, Optical Microlithography XXVII. 9052. doi:10.1117/12.2046352. Retrieved 10 May 2024.
  24. ^ Mitra, Ina (September 2022). "ZERODUR: a glass-ceramic material enabling optical technologies". Optical Materials Express. 12 (9): 3563. doi:10.1364/OME.460265. Retrieved 10 May 2024.
  25. ^ Pinckney, Linda R. (2003). "Glass-Ceramics". Encyclopedia of Physical Science and Technology (Third Edition): 807–816. doi:10.1016/B0-12-227410-5/00293-3. Retrieved 10 May 2024.
  26. ^ "ZERODUR® Extremely Low Expansion Glass Ceramic: SCHOTT Advanced Optics - SCHOTT AG". www.schott.com. Retrieved 15 April 2018.
  27. ^ Cite error: The named reference optomechanicalservices.com was invoked but never defined (see the help page).
  28. ^ Hartmann, P. (18 December 2012). "ZERODUR - Deterministic Approach for Strength Design" (PDF). Optical Engineering. 51 (12). NASA: 124002. Bibcode:2012OptEn..51l4002H. doi:10.1117/1.OE.51.12.124002. S2CID 120843972. Retrieved 11 September 2013.
  29. ^ Senf, H; E Strassburger; H Rothenhausler (1997). "A study of Damage during Impact in Zerodur" (PDF). J Phys IV France. 7 (Colloque C3, Suppltment au Journal de Physique I11 d'aotit 1997): C3-1015-C3-1020. doi:10.1051/jp4:19973171. Retrieved 31 August 2011.