GROWTH OF SAPPHIRE DISKS FROM THE MELT BY A GRADIENT FURNACE TECHNIQUE

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Abstract:

Single crystal Al2O3 sapphire is a candidate material for various window applications. A gradient furnace technique has been developed for the growth of large sapphire disks, 7.3 cm in diameter and 1.5 cm thick, from the melt in molybdenum crucibles. The disks are free of gas bubbles and inclusions and consist of several large pie-shaped grains. Within the grains dislocation densities of 100,000sq.cm. have been measured. The disks are essentially transparent to radiation from wavelengths of 0.25 micrometers in the ultraviolet spectrum to 4.5 micrometers in the infrared spectrum.

Author(s):
Schmid, Frederick ; Viechnicki, Dennis J.
Author Organization(s):
ARMY MATERIALS AND MECHANICS RESEARCH CENTER WATERTOWN MA
Descriptive Note:
Technical rept.
Pagination:
0013

Security Markings

DOCUMENT & CONTEXTUAL SUMMARY

Distribution:
Approved For Public Release
Distribution Statement:
Approved For Public Release; Distribution Is Unlimited.

RECORD

Collection: TR
Identifying Numbers
Report Number(s):
AMMRC-TR-70-11
Project Number(s):
DA-1-T-062105-A-330
Monitor Series:
AMMRC
 Subject Terms
Joint Capability Areas:
JCA_6.3.3_Spectrum Management; JCA_6_Net Centric; JCA_5_Command and Control; JCA_3.2_Engagement; JCA_3_Force Application; JCA_6.3_Net Management; JCA_3.2.1_Kinetic Means; JCA_1.2_Force Preparation; JCA_1_Force Support; JCA_1.2.3_Educating; JCA_6.1.2_Wireless Transmission
Modernization Areas:
Space
Communities of Interest:
Weapons Technologies
Descriptor(s):
*CRYSTAL GROWTH, *SAPPHIRE, *INFRARED WINDOWS, MOLYBDENUM, DISLOCATIONS, BUBBLES, VISIBLE SPECTRA, INFRARED SPECTRA, ULTRAVIOLET SPECTRA, CRUCIBLES, VACUUM FURNACES, ALUMINUM COMPOUNDS, TRANSPARENT PANELS, ARMOR, DENSITY
Field(s)/Group(s):
Crystallography, Optics
Keyword(s):
GAS BUBBLES, FURNACES, GRADIENTS, VERNEUIL PROCESS, CZOCHRALSKI METHOD
Report Date:
1970 Apr 01