LOW-TEMPERATURE SPECIFIC-HEATS OF AGSB ALLOYS

Low temperature specific heats of AgSb alloys of concentrations 0.89; 2.67; 3.7, and 4.72 at% are measured between 0.4 and 4.2 K. Experimental results for pure Ag and AgSb alloys obey the relation C = gamma-T + beta-T3 with an experimental error of 2%. It is observed that the electronic specific heat coefficient, gamma, increases linearly with the impurity concentration while the Debye temperature, theta-D, decreases linearly with the concentration. It is established that the change of gamma on alloying can be expressed as DELTA-gamma = 1/3 c(Z - 1) by modifying the free electron result. Variation of the Debye temperature, theta-D, is believed to result from the change of mechanical properties of Ag. By employing Lindeman's melting theory it is shown that (theta-D)alloy = (1 - 0.63c) (theta-D)Ag which agrees satisfactorily with the experimental results.