Mirror substrate of atomically substituted Na Zr.sub.2 PO.sub.12 low expansion ceramic material
US4587172A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 1, 1984 |
| Grant date | May 6, 1986 |
| Priority date | — |
| Expiry date | Jun 1, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S359/90
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A low expansion ceramic material has a composition represented by the molecular formula i (Na) j (Zr.sub.2-z Na.sub.4z) k (P.sub.3-x Na.sub.x Si.sub.x)O.sub.12 in which the molar proportions i, j and k are each within the range from about 0.9 to about 1.1, and i+j+k equal 3; and, for molar proportions i, j and k each equal to 1.0, the ceramic composition falls within the area defined by the points A, B, C and D in a quarternary diagram of SiO.sub.2, Na.sub.2 O, P.sub.2 O.sub.5 and ZrO.sub.2, the coordinates of the points being: PA0 A: x=0.2, z=0 PA0 B: x=0.6, z=0 PA0 C: x=0, z=0.25 PA0 D: x=0, z=0.125 The ceramic material is especially suitable as a substrate for optically reflecting films.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.