In Situ Observation of Dendrite in Pb_5Ge_3O_(11) Crystal Growth

The whole process of the dendrite growth in PGO melt crystal growth was visualized in the in situ observation system. It was pointed out that the dendrite had relation with the PbO impurity. An concentration diffusive layer arising from the impurity was observed, and the dendrite growth was triggered when the diameter of the layer exceeded the critical value about 12μm. The rate of the main trunk of the dendrite against the time was measured. It was noted that the rate was affected by some factors such as the appearance of the branches and the turning of the main trunk, which was assumed according to our early work.