| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a crystallized glass having an extremely low average linear expansion coefficient from 0°C to 50°C and having an extremely tenuous gradient of aΔL/L curve, more specifically to provide a crystallized glass having an average linear expansion coefficient of 0.0±0.2×10°Cor below from 0°C to 50°C, whose absolute value of the maximal value-minimal value ofΔL/L is 10×10or below from 0°C to 50°C, and whose value of the dCTE/dT-temperature curve between 20°C and 30°C is confined to a range from -1.5 ppb °Cto +1.5 ppb °C.SOLUTION: The provided crystallized glass comprisesβ-quartz and/orβ-quartz solid solution in a state where the variation of the refractive index nd thereof before and after crystallization is 0.04 or less.</p> |
