Silica Carbide Lamps:
Light From A Whisker
This incandescent lamp uses a single crystal of silica carbide for a filment rather than a tungsten
wire. Another material, hafnium carbide, has also been tried in experiments.
The very thin "whisker" filament is stronger than tungsten, and has a high resistance that changes little during the lamp's operation.
A major difficulty lies in growing the single crystals long enought to be useful. The crystals take time to grow and
conditions in the oven must remain very stable.