Growth and characterization of CaCu_3Ti_4O_(12) single crystals

摘要

The CaCu_3Ti_4O_(12) (CCTO) single crystals could be grown from the melt with the nominal composition of Ca:Cu:Ti = l:59:20 in a platinum (Pt) crucible using a self-flux method. The flux-grown CCTO single crystals have well-developed {100} habit planes, and their compositions are close to the ratio of Ca:Cu: Ti=1:3:4. Interestingly, flux-grown CCTO single crystals exhibited two different back reflection Laue patterns; one exhibited only [100] cubic Laue patterns, and the other showed not only [100] cubic Laue patterns but also the satellite spots related to the twin boundary, implying that twin-free CCTO single crystals can be grown by the self-flux method. Both the dielectric constants and losses of twinned CCTO single crystal are significantly higher than those of untwined CCTO crystal at relatively low frequency regime ( ＜ 10 kHz), suggesting that the dielectric property is sensitive to the twin boundary.