Growth of SrTiO₃ Single Crystals with a Diameter of about 30 mm by the Verneuil Method

Abstract

The work demonstrates growth by the Verneuil method of SrTiO3 single crystals of 30 mm in diameter. Experiments are performed under an industrial environment. Growth was for 4.75 h, i.e., within one production shift. The optimum growth conditions for which the length of the region with bubbles D is zero and the effective length EL (i.e., the crystal length of commercial value) is maximized are for the amount of SrCO3 additive of ∼3 wt % and for H2 outer flow rate of ∼35 L/min. These two parameters show the strongest influence on the bubble-free growth, but other growth parameters (H2 inner flow rate, O2 flow rate increase, rotation speed) were also optimized. Selected crystals are characterized from the structural, microstructural, optical, and THz spectroscopy viewpoints, and they are compared with a commercial substrate and with crystals reported in the literature. This work opens the possibility for the industrial growth of large SrTiO3 single crystals and commercialization of large area substrates.

TiSr antisite: An abundant point defect in SrTiO3

“…Theoretical calculations also predict that forming of a Ti Sr -V O pair is energetically favorable 5,6 . We also suggest that the 185 ps lifetime observed in many earlier reports 13-20 , based on measurements in commercial SrTiO 3 crystals grown by the Verneuil method in addition to Cz and EFG methods, is also the Ti Sr antisite instead of the V Ti proposed in those reports, as Verneuil growth tends to lead to material rich in Ti as well 44 . Table I,…”

Finite Element Simulation of Temperature Distribution in Growth Chamber for Verneuil‐Grown SrTiO3 Crystal

“…and Iakoubovskii et al have succeeded in the growth by Verneuil method of SrTiO 3 single crystals of 30 mm in diameter. [6,7] The commonly employed technique for commercial production of SrTiO 3 is the Verneuil method.…”

“…[12][13][14][15][16] The growth conditions of structural perfection SrTiO 3 grown by Verneuil method have been published. [2,6] The patents and publications do not contain all the necessary data on the experimental conditions for growth of large SrTiO 3 crystals. However, there are little publications about numerical analysis of combustion characteristics in growth chamber for growing SrTiO 3 by Verneuil method.…”