GROWTH OF 3-INCH-DIAMETER LI2B4O7 SINGLE-CRYSTAL USING THE RESISTANCEHEATING FURNACE

The mode and origin of cracking of lithium tetraborate (Li2B4O7) singl e crystals during growth using a resistance heating furnace have been studied. The relationship between the formation mechanism of anomalous growth ridges and the occurrence of cracking was examined. It is conc luded that a high temperature gradient near the interface and small te mperature fluctuations in the melt are needed for growing a crack-free 3-inch-diameter Li2B4O7 single crystal.