| Title |
Dendrite Tip Shapes of Pivalic Acid-Ethanol and Succinonitrile-Salol Systems |
| Authors |
석명진(Myung Jin Suk); 박영민(Young Min Park); 오승탁(Sung Tag Oh); 장시영(Si Young Chang) |
| DOI |
https://doi.org/10.3365/KJMM.2011.49.7.570 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
crystal growth; solidification; interfaces; anisotropy; dendrite tip morphology |
| Abstract |
The shape of a dendrite tip has long been approximated by a paraboloid of revolution, but many attempts have been made as well to more accurately match the dendrite tip profile using other mathematical functions: power function, 4th order polynomial, and hyperbolic function. In the present work, dendrite tip shapes were matched by parabolic function. The differences between the dendrite tip shapes of pivalic acid(PVA)-ethanol(Eth) and succinonitrile(SCN)-salol systems, characterized by anisotropic and isotropic solid-liquid interfacial properties, respectively, were quantitatively treated using shape parameters. The PVA-Eth system showed a slightly higher Z/R value than the SCN-salol system, their Z/R values lying in the range 2-4. (Z is the distance from the tip beyond which the parabolic fit starts to deviate from the profile, and R the tip radius.) λP is the distance from the tip beyond which side branching starts to appear, and is larger in the PVA-Eth system than the SCNsalol system. λP is different for both sides of the 2-dimensional dendrite profile. The difference of λP between both sides of the dendrite is larger for PVA-Eth system than for SCN-salol, implying that the dendrite of PVA-Eth is less symmetric than that of SCN-salol. |