In this study, we examined the effects of the float-zone length, the growth rate, the heating range and the crystal diameter on surface temperature distribution profiles and temperature gradients for a barium titanate single-crystal rod using an LHPG system. The results indicated that the axial surface temperature gradients were enlarged by decreasing the float-zone length and the width of heating range and increasing the growth rate and the diameter of the crystal. During the growth of a 0.7 mm diameter crystal rod at 0.6 mm/min, a growth rate with a narrow heating range and with a high maximum temperature gradient is high, about 2050 degrees C/mm, screw cracks periodically appearing on the crystal surface. (C) 1999 Elsevier Science B.V. All rights reserved.
