RING DEPRESSION TECHNIQUE FOR MEASURING SURFACE-TENSION OF MOLTEN GERMANIUM

A convenient ring technique (ring depression technique, hereafter) has been newly developed for measuring the surface tension of molten germ anium. The validity of this technique is demonstrated through comparis on with the results of the sessile drop technique. The temperature gra dient of germanium surface tension K = d gamma/dT of -0.08 x 10(-3) N/ mK obtained using the ring depression technique showed a good agreemen t with the result obtained by using the sessile drop technique. Moreov er, in relation to maximum surface tension, the difference was within 13% between the results obtained by using the two techniques. Our newl y developed technique provides a method for measuring surface tension which excludes reaction between the probe and the molten germanium. Th is paper describes the ring depression technique for the first time. ( C) 1998 Elsevier Science B.V. All rights reserved.