Thermopower of Molten Aluminium in Ultrasonic Field
L. Moraru
Department of Physics, Faculty of Sciences, University of Galati, Str. Domneasca nr. 111, 6200 Galati, Romania
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Received: February 24, 2003; revised version September 15, 2003
Temperature dependence on the liquid aluminium thermopower is reported for the range 933--1043 K. In order to highlight the ultrasonic wave effect on the thermoelectric power, the experiments were carried out under similar conditions with and without sonication. The lower values of the thermopower in sonication conditions are explained by the decrease in the melt temperature gradient and due to the specific effects of ultrasound propagation process (acoustic flow and acoustic cavitation). A functional relationship was found, Q=-A/T+BT, where A and B are positive constants. These two terms are regarded as electron--ion collisions and spatial redistribution of conduction electrons in the necessary temperature gradient. The effect of cavitation at high temperature is debated. A good agreement between the experimental data and theoretical models of the transport properties is achieved.
DOI: 10.12693/APhysPolA.104.515
PACS numbers: 72.15.Cz, 43.25.+y