|ACCGE - Ex Situ and In Situ Characterization||
Experimental Determination of the Specific Surface Free Energy of Ruby Single Crystals Using Contact Angle of Liquid Droplets
Suzuki, Takaomi 1
We have already measured the specific surface free energy (SSFE) of synthesized single crystals of chlorapatite, quartz, and ruby. It is well known that the SSFE of equilibrium shape of single crystal is proportional to the length of normal line to the surface from the center of the crystal. The SSFE is significant value to discuss the morphology of crystals, but the studies for the SSFE are only theoretical, but the experimental approach for the relationship between the SSFE and the crystal morphology is very few. We first time introduced the contact angle measurement technique for determination of the SSFE of ruby single crystals. Though the observed SSFE has wide distribution originate from surface heterogeneity, the average value of the SSFE satisfied theoretical requirement. This time we used several shape of ruby single crystals in order to determine the absolute value of the SSFE of each face of the crystal. The heterogeneity of the crystal face, which caused the wide distribution of the SSFE of the identical crystal face is mainly the difference of the step density on the crystal face. We studied the relationship between the SSFE and the growth rate of the faces of the ruby crystals, because it is know that the face with high density of steps has large growth rate. The ideal value SSFE was obtained by extrapolation of the linear relationship between SSFE and the growth rate of the faces of the ruby crystals.
 T. Suzuki, I. Kumeda, K. Teshima, S. Oishi, Chem. Phys. Lett., 421(2006)343.
 T. Suzuki, N. Sugihara, E. Iguchi, K. Teshima, S. Oishi, M. Kawasaki, Cryst. Res. Technol., 42(2007)1217.
 T. Suzuki, E. Iguchi, K. Teshima, S. Oishi, J. Crystal Growth, 310(2008)1398.