Assertion: α cristobalite | /r/HasProperty | more than 80 wt %
Facets:
Source sentences:
text: When the α-cristobalite-containing silica glass according to the present invention is produced by heating to melt a mixture of two or more kinds crystalline silicon dioxide powder with the melting points 20° C. or more apart, with a content of α-cristobalite more than 80 wt %, cracks usually occur in the body of the α-cristobalite-contained silica glass, but even with a content of α-cristobalite of 99 wt %, it is possible that cracks will not occur in a body of the α-cristobalite-containing silica glass, if it is re-heated at a temperature of 1000° C. or higher and thereby a crystal of α-cristobalite is gradually grown.
text: In the case that the α-cristobalite-contained silica glass according to the present invention is produced by heating to melt a mixture of two or more kinds crystalline silicon dioxide powder the melting points of which are different from each other by 20 °C or more, with a content of α-cristobalite more than 80 wt %, cracks usually occur in a body of the α-cristobalite-contained silica glass, but even with a content of α-cristobalite of 99 wt %, it is possible that cracks do not occur in a body of the α-cristobalite-contained silica glass, if it is re-heated at a temperature of 1000 °C or higher and thereby a crystal of α-cristobalite is gradually grown.
text: When the α-cristobalite-containing silica glass according to the present invention is produced by heating to melt a mixture of two or more kinds crystalline silicon dioxide powder with the melting points 20° C. or more apart, with a content of α-cristobalite more than 80 wt %, cracks usually occur in the body of the α-cristobalite-contained silica glass, but even with a content of α-cristobalite of 99 wt %, it is possible that cracks will not occur in a body of the α-cristobalite-containing silica glass, if it is re-heated at a temperature of 1000° C. or higher and thereby a crystal of α-cristobalite is gradually grown.