MEASUREMENT OF THE VELOCITY OF CRYSTALLIZATION AND MELTING BY MEANS OF A PRESSURE RELAXATION PROCESS

A new apparatus for the measurement of the velocity of crystallization and melting is presented. The technique is based on the determination of the pressure relaxation, which can be easily measured. In this pap er the method described is applied to the substances water, gallium an d salol. For all systems the growth and melting rates exhibit a quadra tic dependency on pressure or temperature differences. An exception is salol, which shows a linear melting behaviour. While studying ice, va rious state transitions were examined (water reversible arrow ice I, w ater --> ice III, ice I --> ice III).